Ilk. cîr n. “ship”
A noun for “ship” used to in some linguistic notes in the mid-1930s to illustrate the class plural: círiath. Tolkien first wrote these forms with a short vowel (cir, ciriath), and he vacillated on whether these were Noldorin or Ilkorin words, eventually deciding they were from both languages (PE21/57 noted #28). The proper etymology of the Ilkorin form is unclear; based on the example of gwene < *gwenyā we might expect Ilk. **cere instead.
References ✧ PE21/57