icebreaker
n//ˈaɪsˌbɹeɪkəɹ//isbrytare
(watercraft) A ship designed to break through ice so that it, or other ships coming behind, can navigate on frozen seas.
(figurative) A game, activity, humorous anecdote, etc., designed to ease tension and encourage interaction among individuals in a situation where they do not know each other well.