Slang for a very weak beer with "no body" to it, an inferior beer.

英国俚语，一种酒精浓度很低、味道很淡的蹩脚啤酒。

youdao

It wasn't so much a land of milk and honey, but porridge and weak beer.

BBC: Breakthrough in world's oldest undeciphered writing

Dr Dahl says they had a diet of barley, which might have been crushed into a form of porridge, and they drank weak beer.

BBC: Breakthrough in world's oldest undeciphered writing

Another alternative is to let peripheral Europe leave the zone and rebuild it with Denmark and Sweden as a kind of "dark winter night" economic zone, based on sound principles and weak beer.

BBC: Ten points on the Euro crisis