NONCE

Etymology 1

Noun

nonce (plural nonces)

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

(lexicography) A nonce word.

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

Adjective

nonce (not comparable)

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

Etymology 2

Noun

nonce (plural nonces)

(British, slang, pejorative, prisons) A sex offender, especially one who is guilty of sexual offences against children. [1975]

(British, slang, pejorative) A stupid or worthless person. [2002]

Source: Wiktionary

Nonce, n. Etym: [For the nonce, OE. for the nones, a corruption of for then ones, where n. in then is a relic of AS. m in , dat. of the article and demonstrative pronoun, E. the. See For, Once, and The.]

Definition: The one or single occasion; the present call or purpose; -- chiefly used in the phrase for the nonce. The miller was a stout carl for the nones. Chaucer. And that he calls for drink, I 'll have prepared him A chalice for the nonce. Shak. Nonce word, "a word apparently employed only for the nonce". Murray (New English Dict. ).

Source: Webster’s Unabridged Dictionary 1913 Edition