ʃɪft ˌtɹæns.fɔɹˈmeɪ.ʃən ˌtɹæns.fə(ɹ)ˈmeɪ.ʃən tɹanzmjuːˈteɪʃn̩ an act that changes the form or character or substance of something a qualitative change (physics) the change of one chemical element into another (as by nuclear decay or radioactive bombardment) the transmutation of base metals into gold proved to be impossible