The Collaborative International Dictionary
Complemental air
Complemental \Com`ple*men"tal\, a.
Supplying, or tending to supply, a deficiency; fully completing. ``Complemental ceremony.''
--Prynne.-
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.
Wiktionary
complemental air
n. (context biology English) The air that can be drawn into the lungs in addition to the tidal air, by the deepest possible inhalation.