Synonyms for Complement:

n.

addition, block, capacity, arithmetic, accumulation, backlog, counterpart, correlative, supplement, batch, equal, amount, allocation, allowance. adjunct, collocate, entirety, article, accusative, case, whole, totality, cleft sentence, clause, wholeness, antecedent, allomorph, allophone. balance, acute angle, corresponding angles, remainder, filler, obtuse angle, complementary angles, rest, angle, azimuth, adjacent angles, crook, inclination. enhancement, accompanied, sort, order, heap, layer, pile, organize, arrange, collate, range, enrichment, lay out. combine, consolidate, go with, harmonize, piece together, hang together, complete, match-up, blend. makeup, ingredient, match, constituent, dna. accompaniment (noun)
enrichment.
collection (noun)
corps, assortment, stew, mix, federation, medley, partnership, omnium-gatherum, bloc, college, salad, council, formation.
companion, counterpart (noun)
correlative, addition, totality, filler, enhancement, entirety, rest, remainder, balance, capacity, supplement, counterpart, enrichment.
complement (noun)
full complement.
crew (noun)
body, host, detachment, faction, troupe, group, flock, crowd, division, staff, tribe, coalition, cell, assembly, posse, herd, society, drove, hive, mob, retinue, force, regiment, troop, ring, clan, team, league, junta, outfit, wing, fleet, platoon, fellowship, litter, string, cabal, band, coterie, covey, fraternity, bunch, union, colony, phalanx, clique, circle, assemblage, squad, cadre, crew, school, company, army, gang, battalion, sect, aggregation, bevy, set, collection, detail, brigade, club, nest, pack, party, caucus.
sequel (noun)
supplement.

Other synonyms:

overcapacity, acute angle, corresponding angles, azimuth, adjacent angles, hang together, obtuse angle, crook, complementary angles, overkill. addition, inclination, spare, overrun, enrichment, enhancement, angle, surplus, overflow, constituent, harmonize, dna. consolidate, match-up, ingredient. combine, makeup, excess. blend. go with. match. analogue
counterpart.
Other relevant words:
azimuth, entirety, enhancement, totality, correlative, allowance, adjunct, addition, match, supplement, blend, full complement, match-up, remainder, rest, capacity, overcapacity, ingredient, balance, constituent, wholeness, equal, inclination, complete, surplus, overrun, enrichment, excess, counterpart, filler.