Under the Kosh!

anybody know if its "under the kosh" or under the cosh and where did the phrase come from thanks a million

Can you provide a context? Could be: Kosh who is a fictional character in Babylon 5 or cosh which is a blackjack; a piece of metal covered by leather with a flexible handle; used for hitting people (per Google)

- It's cosh, as in "weighted stick" and it means "under threat or coercion". My Cassell's Dictionary of Slang says it is a 1950s phrase, but relates it to a late 19th century American phrase "under the gun", with a similar meaning.

Or: Osh Kosh B'Gosh.