"irascible, quick to take offense; spiteful," 1560s, from wasp + -ish. Related: Waspishly; waspishness.
Entries linking to waspish
wasp n.
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).
-ish
adjectival word-forming element, Old English -isc "of the nativity or country of," in later use "of the nature or character of," from Proto-Germanic suffix *-iska- (cognates: Old Saxon -isk, Old Frisian -sk, Old Norse -iskr, Swedish and Danish -sk, Dutch -sch, Old High German -isc, German -isch, Gothic -isks), cognate with Greek diminutive suffix -iskos. In its oldest forms with altered stem vowel (French, Welsh). The Germanic suffix was borrowed into Italian and Spanish (-esco) and French (-esque). Colloquially attached to hours to denote approximation, 1916.
The -ish in verbs (abolish, establish, finish, punish, etc.) is a mere terminal relic from the Old French present participle.