icebreaker Syllabification: (ice·break·er)Pronunciation: /ˈīsˌbrākər/Definition of icebreaker noun a ship designed for breaking a channel through ice. a thing that serves to relieve inhibitions or tension between people, or start a conversation. a thing that breaks up moving ice so as to lessen its impact, especially a structure protecting the upstream end of a bridge pier. icebreaker in other Oxford dictionaries Definition of icebreaker in the British & World English dictionary