need not

need not (third-person singular simple present needs not, present participle needing not, simple past and past participle needed not)

1. (chiefly UK, auxiliary, indicating absence of necessity) do not have to, do not need to.
   • 2013, Alan Chalmers, What is this thing called Science?, University of Queensland Press, page 36:

     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.

2. (auxiliary, indicating inadvisability) Ought not to.
   • 2018 June 1, Gerard Letterie, “Education is the beacon that lights our path forward in America”, in The Seattle Times:

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

In one sense used to show that something is not necessary, indicating non-obligation or non-inevitability. In another sense used to indicate that something should not be done because it is futile. Can be used in either sense without inflectional change for singular and plural subjects alike.

• not have to
• needn't

• Edenton, endnote, tenoned