newsreader
Anchor person of a news show on television.

• "Give 'em a lifelong siesta, I would," snarled Uncle Vernon over the end of the newsreader's sentence...
  - Vernon Dursley on the Spanish baggage-handlers' strike (OP1)

nicking
Stealing.

• "Well, we'd better get downstairs for your surprise party, Harry - Fred and George should have nicked enough food from the kitchens by now."
  - Ron (GF21)

• "'Ere, Dung, where didja get all them toads from? 'Cos some son of a Bludger's gone and nicked all mine!"
  - Mundungus to Fred, George, and Ron (OP5)

• "But, you know, Will nicked 'em orf Warty Harris in the first place so I wasn't really doing nothing wrong."
  - Mundungus to Molly (OP5)

nosh
Food, a light meal (from a Yiddish term meaning 'to nibble') (NSOED).

• "Excellent nosh, Petunia"
  - Marge, at dinner on Privet Drive (PA2)

nutter
Crazy person.

• "Dad, we met Draco Malfoy in the woods, and he as good as told us his dad was one of those nutters in masks!"
  - Ron to Arthur Weasley (GF9)

• "Talon-clipping by charms...treating scale-rot... This is no good, this is for nutters like Hagrid who want to keep them healthy."
  - Harry to Hermione, researching dragons (GF20)