"equipped for battle," early 13c., past-participle adjective from arm (v.).

1940s, Armed Forces slang, short for gunnery sergeant.

"a little bit," Korean War armed forces slang, from Japanese sukoshi "few, little, some."

"one who serves or has served in the armed forces," 1899, from service (n.) + man (n.).

"re-enlist," by 1906, U.S. armed forces slang, from re- "back, again" + up (v.) "enlist." Related: Re-upped; re-upping.

1844, with reference to armed forces; from volunteer + -ism. In reference to volunteer labor in community activities, by 1977.

"convict," 1956, from yard (n.1) + bird (n.1), from the notion of prison yards; earlier it meant "basic trainee" (World War II armed forces slang).

"gold in the form of a brick," 1853, from gold (adj.) + brick (n.). Meaning "shirker" is from 1914, World War I armed forces slang, from earlier verb meaning "to swindle, cheat" (1902) from the old con game of selling spurious "gold" bricks (attested by 1881).

1560s, "a fight," originally especially "a fight between two armed persons" (later distinguished as single combat, 1620s), also in a general sense of "any struggle or fight between opposing forces," from French combat (see combat (v.)).

1922, "waste time;" 1941; "make a mistake," from goof (n.). Goof off is from 1941, originally World War II armed forces, "to make a mistake at drill;" by 1945 as "to loaf, waste time," also as a noun for one who does this. Related: Goofed; goofing.