from
The Collaborative International Dictionary of English v.0.48
Complemental \Com`ple*men"tal\, a.
1. Supplying, or tending to supply, a deficiency; fully
completing. "Complemental ceremony." --Prynne.
[1913 Webster]
2. Complimentary; courteous. [Obs.] --Shak.
[1913 Webster]
{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} (Zool.), peculiar small males living
parasitically on the ordinary hermaphrodite individuals of
certain barnacles.
[1913 Webster]