From Proto-Finnic *onci, from Proto-Finno-Ugric *omte (“cavity”) or *oŋte. Cognate with Veps onduz, Erzya ундо (undo, “hole, cavity, hollow”) and Hungarian odú (“haunt, animal hole”).
onsi (rare)
| Inflection of onsi (Kotus type 28*J/kynsi, nt-nn gradation) | ||||
|---|---|---|---|---|
| nominative | onsi | onnet | ||
| genitive | onnen | onsien | ||
| partitive | ontta | onsia | ||
| illative | onteen | onsiin | ||
| singular | plural | |||
| nominative | onsi | onnet | ||
| accusative | nom. | onsi | onnet | |
| gen. | onnen | |||
| genitive | onnen | onsien onttenrare | ||
| partitive | ontta | onsia | ||
| inessive | onnessa | onsissa | ||
| elative | onnesta | onsista | ||
| illative | onteen | onsiin | ||
| adessive | onnella | onsilla | ||
| ablative | onnelta | onsilta | ||
| allative | onnelle | onsille | ||
| essive | ontena | onsina | ||
| translative | onneksi | onsiksi | ||
| abessive | onnetta | onsitta | ||
| instructive | — | onsin | ||
| comitative | See the possessive forms below. | |||