英语词源字典 - 在线词源网站

GI [GI 词源字典]: GI: [20] GI originated, around the beginning of the 20th century, as a US abbreviation of galvanized iron. It was soon in common use in the military, in contexts such as GI can, and the idea seems to have got about that it stood for not galvanized iron but government issue. This misconception propelled it into such combinations as GI shoe, GI soap and (facetiously) GI soldier. By the 1930s this had been shortened to simply GI, designating an enlisted man in the US Army.
[GI etymology, GI origin, 英语词源]
enlist (v.): also inlist, 1690s (trans.), 1753 (intrans.), from en- (1) "make, put in" + list (n.). Possibly suggested by Dutch inlijsten "to write on a list." Related: Enlisted; enlisting.
fencible (adj.): early 15c., "capable of making a defense," short for defensible; also see fence (n.). As a noun, "soldier enlisted to defend against invasion and not liable to serve abroad" (1796).
re-enlist (v.): also reenlist, 1828, from re- "back, again" + enlist. Related: Re-enlisted; re-enlisting.
retread (v.): "to put a new tread on (a tire)," 1908, from re- "back, again" (see re-) + tread (q.v.). The noun is attested from 1914; in World War I it was Australian slang for "a re-enlisted soldier."