I was about to say: 'laissez-faire' IS an adjective in English (stolen from the French of course...heh). Adding to James' notes, you can also call it a "whatever" attitude, but the awesome super-long synonym is "lackadaisical".

relaxed, laid-back, almost not caring For example: John displayed a laissez-faire attitude towards his studies. (i.e. he didn't care too much and made little effort)

There are not really adjectives for this. This is a saying that is from French. It literally means " to be and let be" but is mainly used in business or in politics to mean > allowing industry to be free from state intervention (or regulation). It doesn't just mean "whatever" or not caring. It means caring enough to let things run naturally without intervention.

What's the context?