Contraction of ne + y.

nothing works! it's hopeless! it's no use!

negative form of y a-t-il; isn't there? aren't there? (after a modal adverb or jamais) there isn't, there aren't

(idiomatic) to have no responsibility (for it); to have no part (in it), to have nothing to do (with it)

(dated) to see stars after receiving a physical blow / (by extension) to be unable to see the finer details of a complex situation; (particularly) to fall for (a deception), to be taken in, to be totally hoodwinked

there's a fine line between... (said of things that are very close to one another, such that one could easily lead to the other)

to fall for it, to be taken in, to be totally hoodwinked

don't mention it, not at all, think nothing of it, you're welcome

there is no one, there isn't a soul

(idiomatic) It’s not that bad; said to de-dramatize an event