fɔɹ.ˈmeɪ.ʃən fə(ɹ).ˈmeɪ.ʃən ˈplæstɪk ˈplæstɪk forming or capable of forming or molding or fashioning a formative influence a formative experience the plastic forces of nature the act of fabricating something in a particular shape any process serving to define the shape of something