“un croque-mort” (an undertaker) :
“croque ” means “to bite”, “mort ” means “dead”
In the past people used to check if the body was dead, in biting one of his toes.
“qui dort dine” : “who is sleeping, is eating”
Everybody thinks it means that when we sleep we don’t feel hungry and don’t need to eat.
In fact, in the past it was an advert for hostels :
Customers were paying for the bed and the diner was free.
“L’habit ne fait pas le moine” : “the habit doesn’t make the monk”
means : don’t judge people according to their appearance.
“Pierre qui roule n’amasse pas mousse” :
“Pierre qui roule ” : “A rolling stone ”
“ n’amasse pas mousse ” : “isn’t covered with moss ”
(no link with Mick Jagger and Kate Moss)
means we never become rich if we too often change of country, job….
“Quand on veut noyer son chien, on dit qu’il a la rage”
“When we want to drown one’s dog, we say he’s got the rage”
means : when we want Saddam’s oil, we say he’s got mass murder weapons.
“Qui sème le vent récolte la tempête” :
“Who sows the wind harvests the storm”
means : somebody who causes disorder shouldn’t be surprised to get a disaster
“un(e) de perdu(e), dix de retrouvé(e) ” :
“one lost, ten back ”
often said when your boy(girl)friend goes away :
you’ll soon find several better occasions.
“une hirondelle ne fait pas le printemps ” :
“a swallow/martin doesn’t make springtime ”
means : you can’t judge on only one example
“c’est l’hôpital qui se moque de la charité ” :
“it’s the hospital which laughs at the charity”
when we laugh at somebody else who shares the same failings.
“avoir des cornes ” : “to have horns ” :
to be cuckold
“ça ne casse pas 3 pattes à un canard ” :
“that doesn’t break 3 legs at a duck” :
There’s nothing extraordinary
“passer du coq à l’âne ” :
“change from rooster to donkey”
means : changing the subject of the conversation
The Alternative French Dictionary
(good examples but be careful in using it with French people, sometimes it’s very rude)