英语词源字典 - 在线词源网站

blooper (n.)[blooper 词源字典]: "blunder," 1943, apparently first in theater, from American English baseball slang meaning "a fly ball in a high arc missed by the fielder" (1937) or else from the earlier sense "radio receiver that interferes with nearby sets" when a careless operator throws it into oscillation (1926), in which case it imitates the resulting sound.[blooper etymology, blooper origin, 英语词源]
fly (n.): Old English fleoge "a fly, winged insect," from Proto-Germanic *fleugon "flying insect" (cognates: Old Saxon fleiga, Old Norse fluga, Middle Dutch vlieghe, Dutch vlieg, Old High German flioga, German Fliege "fly"); literally "the flying (insect)" (compare Old English fleogende "flying"), from same source as fly (v.1).

Originally any winged insect (moths, gnats, beetles, locusts, hence butterfly, etc.) and long used by farmers and gardeners for any insect parasite. Flies figuratively for "large numbers" of anything is from 1590s. Plural flien (as in oxen, etc.) gradually normalized 13c.-15c. to -s. Fly in the ointment is from Eccles. x:1. Fly on the wall "unseen observer" first recorded 1881. No flies on _____ "no lack of activity or alertness on the part of," is attested by 1866. Meaning "fish-hook dressed to resemble an insect" is from 1580s; Fly-fishing is from 1650s. Fly-catcher "bird which eats insects on the wing" is from 1670s. The fly agaric mushroom (1788) so called because it was used as a poison for flies.

The sense of "a flight, flying" is from mid-15c. From the verb and the notion of "flapping as a wing does" comes the noun sense of "tent flap" (1810), which was extended to "strip of material sewn into a garment as a covering for buttons" or some other purpose (1844). Baseball fly ball attested by 1866. To do something on the fly is 1856, apparently from baseball.
When the catcher sees several fielders running to catch a ball, he should name the one he thinks surest to take it, when the others should not strive to catch the ball on the fly, but only, in case of its being missed, take it on the bound. ["The American Boys Book of Sports and Games," New York, 1864]
fungo (n.): "A fly ball hit to a player during fielding practice in which the batter (often a coach) tosses the ball into the air and hits it as it descends with a long and narrow bat." [Paul Dickson, "The Dickson Baseball Dictionary," 3rd ed., 2009], attested from 1867 (fungoes), baseball slang, of unknown origin; see Dickson's book for a listing of the guesses. Perhaps from a Scottish fung "to pitch, toss, fling;" perhaps from some dialectal fonge "catch," a relic of Old English fon "seize" (see fang), or possibly from the German cognate fangen. Not in OED 2nd ed. (1989). There does not seem to have been a noun phrase (a) fun go in use at the time. It formally resembles the Spanish and Italian words for "fungus."
shag (v.2): in baseball, "to go after and catch" (fly balls), by 1913, of uncertain origin. Century Dictionary has it as a secondary sense of a shag (v.) "to rove about as a stroller or beggar" (1851), which is perhaps from shack (n.) "disreputable fellow" (1680s), short for shake-rag, an old term for a beggar.