N'importe quoi: What does it mean and how is it used?

Question

Can someone explain the meaning and common usages of this phrase? I hear it often and am not entirely sure I always understand it. Does it mean something like English's “whatever” or “bullshit”? Is it said flippantly? Angrily? I would love to see some examples of situations or usages of the phrase so I can get a better grasp on it.

Answer 1

Bullshit

N'importe quoi can mean Bullshit.

— Les poules peuvent voler.
— N'importe quoi !

Could be translated in (without sounding as rude as in English in my opinion)

— Chicken can fly.
— Bullshit!

But you can also use it for all wrong

— Tu as fait n'importe quoi!

Meaning

— You did it all wrong!

(Literally “You did whatever randonmly occurred to you”)

Whatever / I don't mind

If you want to use it as whatever or I don't mind, you shall use peu importe or n'importe

— Que veux-tu manger ?
— Peu importe.

— Tu veux t'asseoir devant ou derrière ?
— N'importe.

Meaning

— What do you want to eat?
— Whatever.

— Do you want to sit at the rear or at the front?
— I don't mind.

What a nonsense

As suggested by RomainVALERI in the comments, n'importe quoi can also be used for pointing out how nonsensical / shameful something is.

— Ils ont réussi à faire de la pub dans les écoles ! C'est n'importe quoi...

which could be translated as

— They managed to put advertising material in schools! What a nonsense...

Answer 2

The "basic" translation is whatever.

For the more idiomatic use I guess almost literal translations like:

• Nobody is thinking about what it is like
• (almost) anything possible
• Whatever (you can imagine)

can give a hint. Moreover the expression is ueds in a negative way, meaning that someone is making almost all he/she can to achieve his/her worst :)

Some other translation could be

• All the worst you can think of

even if it is a bit too strong, since "N'importe quoi" can be used also in an ironic/joking context.