Ondonórë, #Ondórëplace-name "Gondor" (Stone-land). The shorter form of the name is attested in the genitive in the phrase aran Ondórëo, “a king of Gondor”. (VT42:17, VT49:27)
onëconj. "but" (VT43:23)
ónë one pa.t. of onta- vb. "beget, create" (the pa.t. may also be ontanë) (ONO)
ongwënoun “crime” (PE17:170)
óni, see ó-
onnanoun "creature" (ONO), “child” (PE17:170), also translated "child" in the plural compound Aulëonnar "Children of Aulë", a name of the Dwarves (PM:391), and apparently also used = “child” in the untranslated sentence nai amanya onnalya ter coivierya(“k”) *”be it that your child [will be] blessed thoughout his/her life” (VT49:41). The form onya (q.v.), used as a vocative *"my child", is perhaps shortened from *onnanya.
onoconj. "but" (VT43:23, VT44:5/9)
onóna (1) adj. "twin-born"; (2) noun "one of a pair of twins"; pl. ónoni "twins" (WJ:367)
onónë see onórë
onórënoun "sister" (of blood-kin) (THEL/THELES, NŌ; both of these entries in the Etymologies as reproduced in LR have the reading "onóne", but the "Old Noldorin" cognate wanúre listed in the entry THEL/THELES seems to indicate that the Quenya word should be onórë; the letters n and r are easily confused in Tolkien's handwriting. There is no clear evidence for a feminine ending -në in Quenya, but -rë is relatively well attested; cf. for instance ontarë.) – A later source gives the word for “sister” as nésa instead.