Complexes rhymes with:
reflexes, latexes, reflexes, abraxa's, abraxas, ajax's, axa's, boxes, fox's, foxes, hyraxes, latexes, mixes, reflexes, sexes, taxes
Complexes sounds like:
camouflage, campbell's, campbells, cannibalize, cannibals, chambless, chambliss, cineplex, cineplex's, commonplace, compels, compiles, complex, complies, conable's, convalesce, cosmopulos, cymbals