blow the gaff

3 definitions

0—

#1·2h ago

Blow the gaff is a British slang phrase meaning to reveal a secret, spill the beans, or rat someone out. Though dated, the expression still surfaces in British crime fiction, period dramas, and from older speakers who enjoy its old-school flavour. To blow the gaff is to expose what was meant to stay hidden — whether that's a scam, a surprise, or someone's criminal activity. The 'gaff' here refers to a secret or trick, not a place.

Don't invite him along — he'll blow the gaff about the surprise party the second he has a drink in him.

Origin: 18th-century British cant. 'Gaff' in this context meant a trick or secret; 'blow' meant to expose or reveal, as in 'blow the cover'. Editorial expansion authored on Slangora (model-assisted, hedged).

Was this helpful?

Comments (0)

No comments yet — say something.

0—

#2·1d ago

(UK, slang, obsolete) To disclose a secret.

Origin: Origin information sourced from Wiktionary contributors (CC BY-SA 4.0).

Was this helpful?

Comments (0)

No comments yet — say something.

0—

#3·1d ago

(UK, slang, obsolete) To inform against a person.

Was this helpful?

Comments (0)

No comments yet — say something.

Have a better definition?

Add your own interpretation of "blow the gaff".

Add definition

⚡About Tech, Dev & AI slang

The vocabulary of software engineers, AI researchers, and anyone living in a terminal or on GitHub — from LLM to MCP, CORS to vibe coding, agentic to enshittification.

See all Tech, Dev & AI slang on Slangora.