alteration, alternation, avatar, battledore and shuttlecock, catabolism, catalysis, commutation, consubstantiation, cooperation, counterchange, cross fire, displacement, exchange, give-and-take, heterotopia, innovation, interchange, intermutation, interplay, lex talionis, measure for measure, metabolism, metagenesis, metamorphism, metamorphosis, metastasis, metathesis, metempsychosis, modification, mutant, mutated form, mutation, mutual admiration, mutual support, mutual transfer, mutuality, novelty, quid pro quo, reciprocality, reciprocation, reciprocity, reincarnation, retaliation, something for something, sport, tit for tat, transanimation, transfiguration, transfigurement, transformation, transformism, translation, translocation, transmigration, transmogrification, transmutation, transposal, transposition, transubstantiation, vicissitude