гриза

Etymology 1
.

Verb

 * 1)  to gnaw (at), to nibble (at), to eat into
 * 2)  to fester, to rankle, to fret
 * 1)  to fester, to rankle, to fret
 * 1)  to fester, to rankle, to fret
 * 1)  to fester, to rankle, to fret

Etymology 2
From secondary, syncretized into the conjugation of Etymology 1. Obsolete гри́зе is expected from titular.