avoir de l’eau dans la cave

to be wearing trousers that are too short

Said of someone whose trousers ride up short enough to show their socks, as though they had hitched them up to keep dry from a flood down in the basement. Belgians mostly say dans les caves and the Swiss à la cave; this singular form is the one heard in Moselle and Canada.

Avec un pantalon pareil, il a de l’eau dans la cave.

With trousers like that, he must be expecting a flood.

Origin uncertain.

BelgiumSwitzerlandMoselleCanada