CIS- Meaning of CIS- in English cis- combining form BrE AmE ¦sɪs▷ — cis-butadiene ˌsɪs ˌbjuːt ə ˈdaɪ iːn AmE \ -ˌbjuːt̬- Longman Pronunciation English Dictionary. Английский словарь произношений Longman. 2012