Wiktionary
irregular verb
n. A verb that does not follow the normal rules for its conjugation.
Usage examples of "irregular verb".
I had finished my written work, but had my Varnian grammar book open before me, going over some irregular verb forms.
Very early in their recapitulation of the imperfect subjunctive of the irregular verb stare Mrs Fielding saw with alarm that her pupil's conduct was likely to grow even more irregular than her verb.