"one who makes or sells salt," Old English sealtere; see salt (n.).

"quality or condition of being salt," 1660s, from salty + -ness. Earlier was simply saltness, from Old English sealtnes.

also saltier, c. 1400, sautour, an ordinary that resembles a St. Andrew's Cross on a shield or flag, consisting of a bend dexter and a bend sinister crossing each other, from Old French sautoir, sautour, literally "stirrup," and directly from Medieval Latin saltarium, noun use of neuter of Latin saltatorius "pertaining to leaping," from salire "to leap" (see salient (adj.)). The connection between stirrups and the diagonal cross is said to be the two deltoid shapes that comprise the cross.

"somewhat salt, salty," late 15c., from salt (n.) + -ish.

"place resorted to by animals to satisfy the natural craving for salt," 1751; see salt (n.) + lick (n.).

"salt-water marshland," Old English sealtne mersc; see salt (n.) + marsh. 

"potassium nitrate," a chief constituent of gunpowder, c. 1500, earlier salpetre (early 14c.), from Old French salpetre, from Medieval Latin sal petrae "salt of rock," from Latin sal "salt" (from PIE root *sal- "salt") + petra "rock, stone" (see petrous). So called because it looks like salt encrusted on rock and has a saline taste. Spelling was conformed to salt. Related: Saltpetrous.

mid-15c., salti, "tasting of salt, somewhat salt, impregnated with salt," from salt (n.) + -y (2).

The meaning "racy, sexy" is from 1866, from salt in the sense of "that which gives life or pungency" (1570s, originally in reference to words or wit); salt (adj.) also was used of lecherous (female) dogs, etc. (1540s) and also of persons (16c.-17c.).

The U.S. slang sense of "angry, irritated" is first attested 1938 (perhaps from similar use with regard to sailors, "tough, aggressive," which is attested by 1920), especially in phrase jump salty "unexpectedly become enraged" (1938). Related: Saltily.