spittle n.

"saliva," early 14c., from spit (v.1). Meaning "the very likeness" in modern use is attested from 1825 (as in spitting image, attested from 1887); compare French craché in same sense. Spit-curl (1831) was originally considered colloquial or vulgar. Military phrase spit and polish first recorded 1895.

Old English spiwan "spew, spit," from Proto-Germanic *spiew- (source also of Old Saxon spiwan, Old Norse spyja, Old Frisian spiwa, Middle Dutch spijen, Dutch spuwen, Old High German spiwan, German speien, Gothic spiewan "to spit"), from PIE *sp(y)eu- "to spew, spit," probably ultimately of imitative origin (source also of Latin spuere; Greek ptuein, Doric psyttein; Old Church Slavonic pljuja, Russian plevati; Lithuanian spiauti). Also in Old English as a weak verb, speowan. Related: Spewed; spewing.