1. (a.) Supplying, or tending to supply, a deficiency; fully completing.

2. (a.) Complimentary; courteous.

akin aligned alike analogical answering coequal coextending coextensive collatable collateral commensurable commensurate comparable comparative complemental complementary concurrent consonant convertible correlative correspondent corresponding duplicate equal equidistant equipollent equispaced equivalent even homologous interchangeable kindred lined up matchable matching much at one nonconvergent nondivergent of a kind of a piece of a size parallel parallelepipedal parallelinervate paralleling parallelodrome parallelogrammatic parallelogrammic parallelotropic reciprocal reciprocative relative similar tantamount twin undifferentiated uniform