Albedo feature - unusually dark or light
Boulder tracks - narrow grooves left by rolling or sliding rocks and boulders
Catena - a chain of craters
Central peak composition - chemical makeup of crater central peaks
Concentric crater - small crater with two rims, sort of..
Crater - circular depression
Cryptomaria - hidden maria
Dark-halo - low-albedo deposits surrounding some craters
Dorsum - ridge
Floor Fractured Crater -impact morphology modified by volcanic-related activity
Fossa - long, narrow depression
Gulch - According to Wikipedia, a Gulch is a deep V-shaped valley formed by erosion. It may contain a small stream or dry creek bed and is usually larger in size than a gully. Sudden intense rainfall upstream may produce flash floods in the bed of the gulch. (only the people of the NASA and the astronauts of the early Apollo missions used the word Gulch in their nomenclature for certain lunar surface formations, not the IAU).
Lacus - "lake" (small plain)
Landing site name - at or near Apollo landing site
Lunar Basin - extremely large impact craters
Mare - "sea" (large circular plain)
Mesa - According to Wikipedia, a Mesa is an elevated area of land with a flat top, surrounded on all sides by steep cliffs. The people of the IAU never used the word Mesa in their official lunar nomenclature. Only the NASA and the astronauts of the early Apollo missions invented names with the word Mesa in them, such as Barbara Mesa, Lonesome Mesa, etc...
Minor feature - extremely small named craters
Mons - mountain
Montes - mountain range
Oceanus - "ocean" (very large dark area)
Palus - "swamp" (small plain)
Planum - high plain
Planitia - low plain
Promontorium - headland or promontory
Pyroclastic - type of rocks of volcanic origin (see Charles Wood's and Maurice Collins's 21 Century Atlas of the Moon).
Radar bright - radar bright craters are young
Ray craters - craters with prominent 'rays' extending outward
Rima - fissure (Latin) or rille (German for groove)
Rupes - fault
Satellite feature - lettered crater
Sinus - "bay" (small plain)
Swirl - bright areas typically associated with strong magnetic anomalies
Terra - obsolete term for bright highland areas
Thermal anomaly crater - craters that have temperature anomalies during eclipses (described in Moore et al, 1980)
Tholus - small, domical hill
Vallis - valley
Volcano - possible or actual
ALPO - Association of Lunar & Planetary Observers
ASSB - Apollo Site Selection Board (see Don E. Wilhelms: TO A ROCKY MOON; a Geologist's History of Lunar Exploration).
BA - British Association for the Advancement of Science
BAA - British Astronomical Association
DMA - Defense Mapping Agency
GAISH - Sternberg Institute
GDL - Gas Dynamics Laboratory
GIRD - Group for the Study of Reaction Motion
GLEP - Group for Lunar Exploration Planning (see Don E. Wilhelms: TO A ROCKY MOON; a Geologist's History of Lunar Exploration).
GLR - Geological Lunar Researches Group
IAU - International Astronomical Union
JPL - Jet Propulsion Laboratory
JSC - Johnson Space Center
LOPO - Lunar Orbiter Project Office (see Don E. Wilhelms: TO A ROCKY MOON; a Geologist's History of Lunar Exploration).
LPACC - Lunar Photography and Cartography Committee
LPI - Lunar and Planetary Institute
LPL - Lunar and Planetary Laboratory
LRL - Lunar Receiving Laboratory (see Don E. Wilhelms: TO A ROCKY MOON; a Geologist's History of Lunar Exploration).
LSAPT - Lunar Sample Analysis Planning Team (see Don E. Wilhelms: TO A ROCKY MOON; a Geologist's History of Lunar Exploration).
LSI - Lunar Science Institute (see Don E. Wilhelms: TO A ROCKY MOON; a Geologist's History of Lunar Exploration).
LSPET - Lunar Sample Preliminary Examination Team (see Don E. Wilhelms: TO A ROCKY MOON; a Geologist's History of Lunar Exploration).
NASA - National Aeronautics and Space Administration
NSSDC - National Space Science Data Center (see Don E. Wilhelms: TO A ROCKY MOON; a Geologist's History of Lunar Exploration).
PET - Preliminary Examination Team (see LSPET).
RNII - Rocket Research Institute
SOUC - Surveyor/Orbiter Utilization Committee (see Don E. Wilhelms: TO A ROCKY MOON; a Geologist's History of Lunar Exploration).
TGLN - Task Group for Lunar Nomenclature
USGS - United States Geological Survey
WGPSN - IAU Working Group for Planetary System Nomenclature
Acronyms and abbreviations
Alphabetic glossary of APOLLO related abbreviations (compiled by Garry Kennedy for the APOLLO LUNAR SURFACE JOURNAL, Eric M. Jones).
Other interesting sources full of Apollo abbreviations are Volume 1 and 2 of APOLLO 11 - THE NASA MISSION REPORTS (edited by Robert Godwin, Apogee Books, 1999)
AIC - 1:500,000 map series (1/4 of LAC zone, very limited coverage)
CMP - Command Module Pilot (Apollo program)
CSM - Command Service Module (Apollo program)
DEM - digital elevation model
IAU directions - north up, east to right
IAU nomenclature - official system for naming Lunar features
JPL Horizons - online solar system ephemeris
LAC - 1:1,000,000 map series (44 maps, partial coverage, nearside only)
LAC zone - notation defining lunar map area
LM - Lunar Module (Apollo program)
LM map series - 1:1,000,000 map series (updates of LAC series; 11 maps only)
LMP - 1:5,000,000 map series (3 maps, full coverage), also: LMP-Lunar Module Pilot (Apollo program)
LO - Lunar Orbiter
LPOD - Lunar Photo of the Day (website)
LRL - Lunar Receiving Laboratory
LRO - Lunar Reconnaissance Orbiter (the lower half of this page contains an overview of the many contributors of the Arizona State Universitys (School for Earth & Space Explorations) page LROC (which shows hundreds of articles and close-up NAC photographs of selected regions!).
LROC - Lunar Reconnaissance Orbiter Cameras
LTM - early nearside topographic map in east and west hemispheres
LTO - 1:250,000 map series (1/16th of LAC zone, partial coverage in Apollo zone)
LTP - Lunar Transient Phenomena
LTVT - Lunar Terminator Visualization Tool (computer program)
PDS - NASA Planetary Data System for distribution of spaceprobe results
PI - principal investigator
Map-a-Planet - on-line service for interactively creating lunar maps
S-IVB - (or S-4B) - The stage of the Saturn-V rocket which boosted the CSM and LM out of Earth orbit, enroute to the moon (Apollo program)
SIM - Scientific Instruments Module (Apollo program)
Topophotomap -- same as LTO but covers smaller area; various scales; limited coverage
ULCN - Unified Lunar Control Network
VMA - Virtual Moon Atlas (computer program)
Xi-Eta - position of nearside feature in X-Y coordinates
Albedo - the reflectance of a surface
Anaglyph - stereoscopic image composed of two slightly shifted images, both in opposite colors
Apollo 8 - first manned mission to orbit the moon (december 1968).
Apollo 10 - second manned mission to orbit the moon (may 1969). See Apollo 10 Flight Journal (David Woods, Robin Wheeler, Ian Roberts).
Ashen Light (see Earthshine).
Clair-obscur - "features" produced by patterns of light and shadow; also called "Trompe l'oeil"
Colongitude - 90° minus longitude of subsolar point
Conjunction - Moon and Sun in same direction in sky
Earthshine - Earth-to-moon reflected sunlight, also called "Ashen Light"
Elongation - apparent angle between Sun and Moon
Evening Terminator - line of sunset on the Moon
Far Side of the Moon (the hemisphere of the moon which is always invisible for the population on planet Earth) (only 24 astronauts have seen parts of this hemisphere, this during the heydays of Project Apollo, 1968-1972).
First Quarter Moon (see: The Moon's Phases).
Full Moon (see also: The Moon's Phases).
Gibbous Moon (see: The Moon's Phases).
Grazing Lunar Occultation
Last Quarter Moon (see: The Moon's Phases).
Librations - apparent rocking motions of the Moon as viewed from Earth
Limb - the Moon's edge
Lunar Heliotrope Project (Project PHAROS)
Lunar Orbiter - space mission
Lunar theory - mathematical descriptions of the Moon's motions
Lunar Zodiacal Light (and the mystery of the Kordylewski clouds).
Lunation - the interval from one New Moon to the next
Lunar Pyroclastic Volcanism Project - USGS cataloging of volcanic ash deposits
Morning Terminator - line of sunrise on the Moon
Near Side of the Moon (the hemisphere of the moon which is always visible for the population on planet Earth) (aka The Face of the Man in the Moon).
New Moon (see: The Moon's Phases).
North Pole - the moon's pole at 90° North
Opposition - Moon opposite Sun in sky
Opposition Surge - increase in brightness near zero phase angle
Pareidolia - images of living creatures (mostly faces) and other familiar objects seen in Earth's and the moon's surface formations (an optical illusion, often called "Trompe l'oeil"), see also page Clair-Obscur effects on the Moon's Surface (a handy overview of terminator-related optical illusions)
Phase - illuminated fraction of Moon
Phase Angle - angle between Sun and observer as seen from Moon
Phases - named points in the lunar cycle (New, First Quarter, Full, Last Quarter)
Resolution - the size of the smallest detectable detail
Retro-Reflection phenomena - lunar Heiligenschein
Selenographic Coordinates - system of latitude and longitude on Moon
Stratigraphy - system to rank relative age of rocks
South Pole - the moon's pole at 90° South
Sub-Earth Point - location on surface where Earth is directly overhead
Subsolar Point - location on surface where Sun is directly overhead
Sun angle - angle of sun above local horizontal
Synodic month - interval from New Moon to New Moon
Terminator - the line separating the sunlit and shadowed side of the Moon
Transits - telescopic observations of unknown objects crossing the moon's disc (small asteroids?).
Very Old Moon (Waning Crescent Moon slightly before New Moon, see The Moon's Phases).
Very Young Moon (Waxing Crescent Moon slightly after New Moon, see The Moon's Phases).
Waning Crescent Moon (before New Moon - after Last Quarter Moon, see The Moon's Phases).
Waning Gibbous Moon (after Full Moon - before Last Quarter Moon, see The Moon's Phases).
Waxing Crescent Moon (after New Moon - before First Quarter Moon, see The Moon's Phases).
Waxing Gibbous Moon (before Full Moon - after First Quarter Moon, see The Moon's Phases).
Zero-point of Latitude and Longitude (near Oppolzer A).