- smack (n.1)
- "taste, flavor," now mainly in verbal figurative use smacks of ... (first attested 1590s; smack as a verb in this sense is from late 14c.), from Old English smæc, from Proto-Germanic *smak- (cf. Old Frisian smek, Dutch smaak, Old High German smac, German Geschmack); probably related to Lithuanian smaguriai "dainties," smagus "pleasing." Meaning "a trace (of something)" is attested from 1530s.
- smack (n.3)
- "heroin," 1942, American English slang, probably an alteration of schmeck "a drug," especially heroin (1932), from Yiddish schmeck "a sniff."
- smack (v.1)
- "make a sharp noise with the lips," 1550s, probably of imitative origin (see smack (v.2)). Meaning "a loud kiss" is recorded from c.1600. With adverbial force, attested from 1782; extended form smack-dab is attested from 1892, American English colloquial.
- smack (n.2)
- "single-masted sailboat," 1610s, probably from Dutch or Low German smak "sailboat," from smakken "to fling, dash" (see smack (v.2)), perhaps so-called from the sound made by its sails. French semaque, Spanish zumaca, Italian semacca probably are Germanic borrowings.
- smack (v.2)
- "to slap with the hand," 1835, from noun in this sense (c.1746), perhaps influenced by Low German smacken "to strike, throw," which is likely of imitative origin (cf. Swedish smak "slap," Middle Low German smacken, Frisian smakke, Dutch smakken "to fling down," Lithuanian smagiu "to strike, knock down, whip").