French language is very rich in idioms.
Some are very well known and some do not even make sense to the French themselves.
Let’s see some idioms as well as their meaning and history.

The first example is
Un temps de chien ( literally “a weather of dog” ).

A common saying to express the bad weather. In French, do not forget that ” temps ” does not only mean ” time ” but also “ weather “.

Example :
” La météo est horrible aujourd’hui. ”
” Oui, quel temps de chien ! “.

Centuries ago, dogs were not the best friends of men thus many sayings have inherited the mistrust and dislike for our puppies.

Rire comme une baleine
( literally” to laugh like a whale ” ).

A saying used to describe someone laughing in a very loud manner, without retinue.

” Cette blague était très drôle. ”
” En effet, Jean rigole comme baleine. ”

The louder one laughs the wider open is mouth is supposed to be and a whale, while eating, definitely shows us the biggest mouth on earth, hence the comparison.

Pas besoin de sortir de Saint-Cyr pour …
(literally “no need to be graduated from Saint-Cyr for/to do something…” ).

Saint-Cyr is a very prestigious French military school, created by Napoléon in 1802. Being graduated from Saint-Cyr is often considered very prestigious and therefore someone who succeeded in Saint-Cyr is seen as an elite among the elites.

” Pas besoin de sortir de Saint-Cyr pour changer une ampoule ”

The meaning of this saying is simple, you don’t have to graduate from Saint-Cyr school ( or another very prestigious school ) and be incredibly intelligent to do complete simple tasks such as changing a light bulb.

Note that this saying is almost made of an other saying. ” Sortir d’une école ” ( literally going out of a school ) does not mean that you have been expelled/fired from a school or you have quit but it means you have succeeded in this school and have been graduated ( imagine that you are going out of this school by the front door ).

Dans de beaux draps
( literally “to be in beautiful – bed – sheets” ).

An old and ironical saying used to describe someone who has put himself in a bad situation.

” Jean s’est mit dans de beaux draps en volant des bonbons “.

This saying certainly goes back to the Renaissance when people said ” dans de beaux draps blancs ”  ( in beautiful white sheets )

We use this saying today for the same reason.

Back in the Middle-Ages and the Renaissance, the white colour was not the representation of purity it has today and ” draps ” was the name of a certain type of clothing. When someone committed an offence, he was usually dressed in white cloths ( ” draps blancs ” ) during the time needed for his redemption thus, being dressed in white sheets was synonym of being in an uncomfortable situation.
The term of ” beaux (beautiful ) ” is ironical and not to be taken in its proper meaning. Nowadays, even if this saying is still used, people tend to say ” dans de mauvais draps ” (literally “in bad sheets” ) for a more literal and comprehensible meaning to this old and funny saying.

Faire un caca nerveux
(literally “to make a nervous poo” )

Usually said to someone getting extremely angry, often for no reason. This is a recent saying, certainly from the beginning of the 20th century.

” Jean fait un caca nerveux parce que sa maman ne veux pas le laisser manger des bonbons”.