ISTHMUS Meaning of ISTHMUS in English nounEXAMPLES FROM CORPUS▪He walked on, crossed the isthmus , and passed the entrance to the docks. ▪Picked a catena from the summit to the isthmus on the east side. Longman DOCE5 Extras English vocabulary. Дополнительный английский словарь Longman DOCE5. 2012