Old English wæps, wæsp "wasp," altered (probably by influence of Latin vespa) from Proto-Germanic *wabis- (source also of Old Saxon waspa, Middle Dutch wespe, Dutch wesp, Old High German wafsa, German Wespe, Danish hveps), from PIE *wopsa-/*wospa- "wasp" (source also of Latin vespa, Lithuanian vapsa, Old Church Slavonic vosa "wasp," Old Irish foich "drone"), perhaps from root *(h)uebh- "weave" (see weave (v.)). If that is the correct derivation, the insect would be so called for the shape of its nest. Of persons with wasp-like tendencies, from c. 1500. Wasp-waist in reference to women's figures is recorded from 1870 (wasp-waisted is from 1775).
"bile, liver secretion," Old English galla (Anglian), gealla (West Saxon) "gall, bile," from Proto-Germanic *gallon "bile" (source also of Old Norse gall "gall, bile; sour drink," Old Saxon galle, Old High German galla, German Galle), from PIE root *ghel- (2) "to shine," with derivatives denoting "green, yellow," and thus "bile, gall." Informal sense of "impudence, boldness" first recorded American English 1882; but meaning "embittered spirit, rancor" is from c. 1200, from the old medicine theory of humors.