Meaning

noun the present occasion

origin1975. Unknown, derived from British criminal slang. Several origins have been proposed; possibly derived from dialectal nonce, nonse (“stupid, worthless individual”) (but this cannot be shown to predate nonce "child-molester" and is likely a toned-down usage of the same insult), or Nance, nance (“effeminate man, homosexual”), from nancy or nancyboy. The rhyme with ponce has also been noted. As…

Etymology from Wiktionary, CC BY-SA 3.0