Catch

n.
  1. Act of seizing; a grasp.
  2. That by which anything is caught or temporarily fastened; as, the catch of a gate.
  3. The posture of seizing; a state of preparation to lay hold of, or of watching he opportunity to seize; as, to lie on the catch.
  4. That which is caught or taken; profit; gain; especially, the whole quantity caught or taken at one time; as, a good catch of fish.
  5. Something desirable to be caught, esp. a husband or wife in matrimony.
  6. A slight remembrance; a trace.
  7. (Mus.) A humorous canon or round, so contrived that the singers catch up each other's words.