This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
齨 combines the tooth radical 齒 with 臼, but the exact historical development and original meaning are uncertain.
The left side is a tooth (齒), and the right side is a mortar (臼). Imagine an old tooth being ground down in a mortar, but remember that the actual meaning is unclear.
For キュウ, picture a tooth (齒) being pulled out with a sudden 'kyu!' sound: kyu -> キュウ, as the tooth is yanked from the mortar-like socket.