English Dictionary

need not

verb

(chiefly UK, auxiliary, indicating absence of necessity) Doesn't have to, don't have to. / (auxiliary, indicating inadvisability) Ought not to.

You need not worry about it.

意味（1）

(chiefly UK, auxiliary, indicating absence of necessity) Doesn't have to, don't have to.

My example illustrates how circularity can arise in arguments that appeal to experiment. But the very same example serves to show that this need not be the case.

意味（2）

(auxiliary, indicating inadvisability) Ought not to.

Want ads for what little manual labor there was frequently had the stipulation INNA, an acronym for Italians and Irish Need Not Apply.