COMPLEMENTAL
complemental, complementary, completing
(adjective) acting as or providing a complement (something that completes the whole)
Source: WordNet® 3.1
Etymology
Adjective
complemental (not comparable)
Of the nature of a complement; completing.
Complementary.
(obsolete) Additional; supplemental, accessory; ancillary.
(obsolete) Of the nature of a ceremony that is not essential but accessory; ceremonial; ceremonious; formal.
(obsolete) Of persons: accomplished; talented; experienced.
(obsolete) Complimentary.
Source: Wiktionary
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 (Zoöl.), peculiar small males living
parasitically on the ordinary hermaphrodite individuals of certain
barnacles.
Source: Webster’s Unabridged Dictionary 1913 Edition