Synonyms and related words :
a propos, ad rem, adapted, alternation, applicable, apposite, appropriate, apropos, apt, becoming, befitting, coaction, complementary distribution, concurrence, cooperation, dovetailing, engagement, felicitous, fit, fitted, fitting, geared, happy, interaction, interchange, intercommunication, intercourse, interlacing, intermeshing, interplay, intertwining, interweaving, interworking, just right, likely, mesh, on the button, opportune, pat, qualified, quid pro quo, relevant, right, seasonable, seesaw, sortable, suitable, suited, suiting, tailored, tit for tat, to the point, to the purpose