mid-15c., "tasting of salt, impregnated with salt," from salt (n.) + -y (2). Meaning "racy" is from 1866, from salt in the sense of "that which gives life or pungency" (1570s, originally of words or wit). Meaning "racy, sexy" is from 1866. U.S. slang sense of "angry, irritated" is first attested 1938 (probably from similar use with regard to sailors, "tough, aggressive," attested by 1920), especially in phrase jump salty "to unexpectedly become enraged." Related: Saltily.
word-forming element denoting action, quality, or state, attached to an adjective or past participle to form an abstract noun, from Old English -nes(s), from Proto-Germanic *in-assu- (cognates: Old Saxon -nissi, Middle Dutch -nisse, Dutch -nis, Old High German -nissa, German -nis, Gothic -inassus), from *-in-, originally belonging to the noun stem, + *-assu-, abstract noun suffix, probably from the same root as Latin -tudo (see -tude).
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Definitions of saltiness
language or humor that is down-to-earth;
self-parody and saltiness riddled their core genre
the saltiness of their language was inappropriate
the taste experience when common salt is taken into the mouth;