Blow cover - Idioms by The Free Dictionary
blow (one's) cover
To expose one's true identity or motives after they had been intentionally concealed (i.e. after one had been "undercover"). The spy fled when he realized that someone had blown his cover. I totally blew my cover when I stupidly wore my school jacket to steal the other team's mascot.
blow someone's cover
Sl. to reveal someone's true identity; to ruin someone's scheme for concealment. The dog recognized me and blew my cover. I didn't mean to blow your cover by calling out to you.
References in periodicals archive
No one has ever been convicted - despite a widely held belief that those who witnessed the blow covered
each others' backs.
| WIDESPREAD DAMAGE: HEAVY BLOW covers
(JH180613Hlinthwaite) one of the manhole covers (JH180613Hlinthwaite) UNDERGROUND explosions blowing heavy manhole covers into the air made the news this week - but not for the first time.
Most of the objects were preserved after a "catastrophic" sand blow covered
them up between the 1770s and the late 1840s.