blow the gaff

Meaning

1. blow the gaff (on sb / sth)

   to tell sth secret, especially by mistake

From the same entry

• blow your brains out
• blow chunks
• blow a fuse
• blow hot and cold
• blow out of the water
• blow smoke
• blow your mind
• blow your own trumpet
• blow your top
• blow up in face
• blow the whistle on
• blow the cobwebs away