take (one) off guard(redirected from take you off-guard)
take (one) off guard
To engage, take advantage of, or seize upon one when one is not especially careful, vigilant, or prepared for danger or surprises. He's got a lot of tricky moves, so make sure he doesn't take you off guard! The soldiers moved in quickly, hoping to take the enemy troops off guard. I think I took him off guard when I told him I was resigning.