Presumably from a verb pern, a variant of preen, from Middle English prene; pernyng is read by some editors in Sir Gawain and the Green Knight (v. 611) and interpreted as the present participle of this verb, also reflected dialectally as pirn (“reel; bobbin”). See also pirl.
- A honey buzzard; Pernis apivorus.
19th century, after the taxonomical name Pernis (Cuvier 1816).
(third-person singular simple present perns, present participle perning, simple past and past participle perned)