stab in the back
when someone you thought was a friend tries to harm you
stab somebody in the back
to do something that harms someone who likes and trusts you SYN betray
stab someone in the back
BETRAY, be disloyal to, be unfaithful to, desert, break one's promise to, double cross, break faith with, sell out, play false, inform on/against, tell on, sell down the river, squeal on, stitch up, peach on, do the dirty on, grass on, shop, rat out, finger, drop a/the dime on, pimp on, pool, put someone's pot on
a stab in the back
stab (someone) in the back to do something harmful to someone who trusted you

[TahlilGaran] English Idioms Dictionary ▲