\Com`ple*men"tal\, a. 1. Supplying, or tending to supply, a deficiency; fully completing. ``Complemental ceremony.'' --Prynne. 2. Complimentary; courteous. [Obs.] --Shak. {Complemental air} (Physiol.), the air (averaging 100 cubic inches) which can be drawn into the lungs in addition to the tidal air, by the deepest possible inspiration. {Complemental males} (Zo["o]l.), peculiar small males living parasitically on the ordinary hermaphrodite individuals of certain barnacles.