A is for Atomic bomb test. Quark and Odo used one to help propel their Ferengi shuttle from 1947 back to the late 24th century.
B is for Boothby. Starfleet Academy caretaker.
C is for c, the speed of light. The real-life maximum speed limit of the universe. Breaking it in Star Trek began the whole adventure.
D is for Deneb IV, visited by both James Kirk and Jean-Luc Picard during their respective Starfleet careers.
E is for Excalbia. Home of powerful rock critters.
F is for Ferengi Marauder, one of the largest warships in the Alpha Quadrant though often crewed by rather inept officers.
G is for Gobbledygook. See technobabble.
H is for Hanoli System, located near Vulcan.
I is for Injectors; antimatter, matter, or warp plasma. Major components of the warp drive.
J is for Jem'Hadar. Attack of the Clones.
K is for Klingon High Command. The highest ranking military officers of their Empire.
L is for Leeta. Holy crap, she's hot.
M is for Miramanee, very briefly the wife of James T. Kirk.