be the cat's whiskers

Meaning

1. be the cat's whiskers / pyjamas

   to be the best thing, person, idea, etc.

   He thinks he's the cat's whiskers (= he has a high opinion of himself).

From the same entry

• let the cat out of the bag
• like a cat on hot bricks
• like a cat that's got the cream
• cat got your tongue
• look like the cat brought in
• not have a cat in hell's chance
• play cat and mouse with
• put the cat among the pigeons
• when the cat's away the mice will play
• curiosity killed the cat
• like herding cats
• be raining cats and dogs