From Wiktionary, the free dictionary
Ultimately from Arabic يَعْنِي (yaʕnī, “(he/she/it) means”).
yəni
- (adverbial, conjunctive, prepositional, or adjectival) in other words, actually, namely, to wit, kind of, somewhat, id est, that is, meaning, you know
- (filler) er, so, uh, well
