noun
a person who deserts one party or cause in order to join an opposing one
adjective
relating to or characteristic of a turncoat
-
The turncoat betrayed his comrades by switching sides during the war.
-
I can't believe she's such a turncoat, she was just praising us yesterday.
-
Don't trust him, he's a total turncoat.
-
Her sudden change of heart made her seem like a turncoat in the eyes of her friends.