Nonce
Either a Shakespearean sounding term for a moment or London criminal slang for one who interferes with the underaged.
Examples:
"Hey nonny nonny, Sirrah,
Prithee, hi thee to an apothecary at the nonce".
or
"Ere. Bullet-tooth Tony says Pelfrey is a nonce".
"Right. Let's do the bastard in association".
It doesn't do to confuse these.