nonce (Noun) — The present occasion. ex. "for the nonce"
nonce (Noun) — (cryptography) a number used once to sign an encrypted communication, e.g. a newly generated random number used to ensure that old communications cannot be reused in replay attacks.
nonce (Noun) — (informal) a paedophile.
nonce (Noun) — (informal) a stupid or worthless person.