run off at the mouth

US /rʌn ɔf æt ðə maʊθ/
UK /rʌn ɔf æt ðə maʊθ/
"run off at the mouth" picture
1.

口无遮拦, 滔滔不绝, 胡说八道

to talk too much, especially in a boastful or indiscreet way

:
He tends to run off at the mouth when he's had a few drinks.
他喝了几杯酒后就容易口无遮拦
Don't tell him your secrets; he'll just run off at the mouth to everyone.
别告诉他你的秘密;他会口无遮拦地告诉所有人。