turn ‧ coat /ˈtɜːnkəʊt $ ˈtɜːrnkoʊt/ BrE AmE noun [countable]
someone who stops supporting a political party or group and joins the opposing side:
Casson was publicly criticized as a turncoat and a traitor.
turn ‧ coat /ˈtɜːnkəʊt $ ˈtɜːrnkoʊt/ BrE AmE noun [countable]
someone who stops supporting a political party or group and joins the opposing side:
Casson was publicly criticized as a turncoat and a traitor.
Longman Dictionary of Contemporary English. Longman - Словарь современного английского языка. 2012