nonce

The one or single occasion; the present reason or purpose.

That will do for the nonce, but we'll need a better answer for the long term.

[...] Dunce, / Dotard, a-dozing at the very nonce, / After a life spent training for the sight!

A nonce word.

I had thought that the term was a nonce, but it seems as if it's been picked up by other authors.

A value constructed so as to be unique to a particular message in a stream, in order to prevent replay attacks.

The protocol opens with A communicating in clear to AS his own claimed identity and the identity of the desired correspondent, B, together with A's nonce identifier for this transaction, I_(A1). ("Nonce" means "used only once.")

The information gained by the eavesdropper would permit a replay attack, but only with a request for the same document, and even that may be limited by the server's choice of nonce.

One-off; produced or created for a single occasion or use. Denoting something occurring once.

But particular men are not stereotyped for jobs nor particular desks (as against others) to sit at - the standard here is nonce.

Dickinson's association of heliotrope with Mary Bowles was nonce and fleeting, but the subject of gardens was always a safe one on which to address her: “How is your garden – Mary? Are the Pinks true –?”

A sex offender, especially one who is guilty of sexual offences against children.

1989 "assorted nonces, ponces and murderers, 'the worst men in the world' … on the nonce wing, where the child-killers, molesters and various perverts have to be protected from the other prisoners." (New Statesman, New Society, Volume 2, Statesman & Nation Publishing Company Limited)

A pedophile.

‘He's a nonce[. A] nonsense merchant, a paedophile[,’ Terry explained.]

A police informer, one who betrays a criminal enterprise

A stupid or worthless person.

Shut it, ya nonce!