Q abbr. 1. a. quarter (of a year) b. quarterly 2. Games queen 3. question q 1 or Q (kyo͞o) n. pl. q's or Q's also qs or Qs 1. The 17th letter of the modern English alphabet. 2. Any of the speech sounds represented by the letter q. 3. The 17th in a series. 4. Something shaped like the letter Q. 5. Q A hypothetical lost manuscript, consisting largely of ...