The one or single occasion; the present reason or purpose (now only in for the nonce).

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

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.

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