What is the X in X-mas?
Old English scot, sceot "a shot, a shooting, an act of shooting; that which is discharged in shooting, what is shot forth; darting, rapid motion," from Proto-Germanic *skutan (cf. Old Norse skutr, Old Frisian skete, Middle Dutch scote, German Schuß "a shot"), related to sceotan "to shoot" (see shoot (v.)).
Meaning "discharge of a bow, missile," also is from related Old English gesceot. Extended to other projectiles in Middle English, and to sports (hockey, basketball, etc.) 1868. Another original meaning, "payment" (perhaps literally "money thrown down") is preserved in scot-free. "Throwing down" might also have led to the meaning "a drink," first attested 1670s, the more precise meaning "small drink of straight liquor" by 1928 (shot glass by 1955). Camera view sense is from 1958. Sense of "hypodermic injection" first attested 1904; figurative phrase shot in the arm "stimulant" first recorded 1922. Meaning "try, attempt" is from 1756; sense of "remark meant to wound" is recorded from 1841. Meaning "an expert in shooting" is from 1780. To call the shots "control events, make decisions" is American English, 1922, perhaps from sport shooting. Shot in the dark "uninformed guess" is from 1885. Big shot "important person" is from 1861.
early 15c., past participle adjective from from shoot (v.). Meaning "wounded or killed by a bullet or other projectile" is from 1837. Figurative sense "ruined, worn out" is from 1833.
A hypodermic injection.
A small amount given or applied at one time.
The detailed end of a process: a book tells you all about that thing, gets into all the short strokes
[1980s+; origin uncertain; perhaps the opposite of broad strokes, broad brush; perhaps a reference to the percussive end of the male orgasm, described in one source in 1916 as the short jerks]