Belt and braces
What's the meaning of the phrase 'Belt and braces'?
'Belt and braces' means being careful - taking double measures to avoid risk. It alludes to the use of both belt and braces to hold up a person's trousers.
What's the origin of the phrase 'Belt and braces'?
Belts and braces (a.k.a. bracers) are meant to hold one's trousers up. Going 'belt and braces' is a double insurance against having them fall down. The figurative use, as a general term for cautiousness, was coined around the mid-20th century in the UK.
The unnecessarily cautious use of both belt and braces was referred to in print before the 'belt and braces' shorthand was coined, as in this example from the UK periodical The Tatler, February 1934:
The gentleman who carried the stepney button on the tip of each tail is probably a confirmed pessimist, and wears a belt and braces,
The first figurative use that I know if is from the UK newspaper The Western Daily Press, September 1942:
A man needs to be "bred up with horses". It is very different to driving a tractor. But a man who has both tractor and a good team horses is wearing both belt and braces.
In the USA 'belt and suspenders' is used with just the same meaning. That link between belt and suspenders and pessimism emerged at around the same time too. The first citation in print I know of is from the California newspaper The San Anselmo Herald, February 1930:
The speaker said... men who wore both belt and suspenders were pessimists.
The figurative use of the phrase 'belt and suspenders', that is, one that doesn't refer directly to clothing, is rarer in the USA. I can find no uses of it that pre-date the UK 1942 example above.