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!

Gnomish

cwancha-

verb. to ail

A word given as {cwanca- >>} G. cwancha- “to ail” in the Gnomish Lexicon of the 1910s, verb form of G. cwanc “sickly” (GL/28).

Neo-Sindarin: For purposes of Neo-Sindarin I would update this word to pavra- “to ail, be ill”, based on the later word [N.] paw “sickness” and its root ᴹ√KWAM (Ety/KWAM).