Qenya
aia-
prefix. other, different (of larger numbers)
Beware, older languages below! The languages below were invented during Tolkien's earlier period and should be used with caution. Remember to never, ever mix words from different languages!
A prefix for “other, different” appearing Demonstrative, Relative, and Correlative Stems (DRC) from 1948 (PE23/99). Tolkien considered several prior forms on the page where it appeared: {asta} >> {aia < asya} >> aia < ᴹ√AYA (PE23/99 note #27). Earlier drafts had {ar} (PE23/101 note #36) >> {ap-, apana-} >> {war- < gwar-} (PE23/102 note #36). Forms appearing in the rest of the document mostly showed {war(a)-} >> ai(a)-.
Neo-Quenya: For purposes of Neo-Quenya, I would use later hya- as the basis for “other” words, as with (pron.) hya “other thing” and (adj.) hyana “other” (VT49/14).