"pertaining to slugs," 1650s, with -ous + Latin limax (genitive limacis) "snail, slug," from Greek leimax, from PIE root *(s)lei- "slime" (see slime (n.)). The Greek word is cognate with Russian slimák "snail," Lithuanian sliekas "earthworm," and the first element in Old English slaw-wyrm "slow-worm."
late 14c., late 13c. as a surname, "habitually lazy person," from Middle English sluggi "sluggish, indolent," probably from a Scandinavian word such as dialectal Norwegian slugga "be sluggish," dialectal Norwegian sluggje "heavy, slow person," dialectal Swedish slogga "to be slow or sluggish." Adjective sluggy is attested in English from early 13c. As an adjective meaning "sluggish, lazy" from 1590s. Related: Sluggardly.
'Tis the voice of a sluggard — I heard him complain:
"You have wak'd me too soon, I must slumber again."
[Isaac Watts, 1674-1748]
'Tis the voice of the Lobster: I heard him declare
"You have baked me too brown, I must sugar my hair."
["Lewis Carroll" (Charles L. Dodgson), 1832-1898]
"a quick blow, dig, or thrust with the fist," by 1570s, probably from punch (v.). In early use it also could refer to blows with the foot or jabs with a staff or club. Originally especially of blows that sink in to some degree ("... whom he unmercifully bruises and batters from head to foot: here a slap in the chaps, there a black eye, now a punch in the stomach, and then a kick on the breech," Monthly Review, 1763).
The figurative sense of "forceful, vigorous quality" is recorded from 1911. Punch line (also punch-line) is from 1915, originally in popular-song writing. To beat (someone) to the punch in the figurative sense is from 1915, a metaphor from boxing (attested by 1913); punch-drunk "dazed from continued punching, having taken so many punches one can no longer feel it" is from 1915 (alternative form slug-nutty is from 1933).
"bus which carries passengers for a fare," 1915, short for jitney bus (1906), American English, from gitney, jetney (n.), said in a 1903 newspaper article to be a St. Louis slang for any small coin, especially "a nickel," (the buses' fare typically was a nickel), the coin name attested or suggested by 1898, probably via New Orleans from French jeton "coin-sized metal disk, slug, counter" (see jetton).
"I'll give a nickel for a kiss,"
Said Cholly to a pretty miss.
"Skiddo," she cried, "you stingy cuss,"
"You're looking for a jitney buss."
["Jitney Jingle," 1915]
The origin and signification of the word was much discussed when the buses first appeared. Some reports say the slang word for "nickel" comes from the bus; most say the reverse, however there does not seem to be much record of jitney in a coin sense before the buses came along (a writer in "The Hub," August 1915, claims to have heard and used it as a small boy in San Francisco, and reported hearsay that "It has been in use there since the days of '49"). Most sources credit it to the U.S. West, especially California, though others trace it to "southern negroes, especially in Memphis" ["The Pacific," Feb. 7, 1915].