This current form is actually a participle of an obsolete form *pojë which is a zero-grade suffixed derivation of *h₃ep-(“to work”). Relationship with Hittite [script needed](ḫappinaḫḫ, “to become rich”) is unclear even though there have been cases in which an older -i- has become a -u- (ahu "beech" is also attested as ahi in older dictionaries), making it possible for this word to have been *pina with a different meaning.