elastomer Syllabification: (e·las·to·mer)Pronunciation: /iˈlastəmər/Definition of elastomer noun a natural or synthetic polymer having elastic properties, e.g., rubber. Derivatives elastomericPronunciation: /iˌlastəˈmerik/ adjective Origin: 1930s: from elastic + -merelastomer in other Oxford dictionaries Definition of elastomer in the British & World English dictionary