Usually a noun, although can also be used as an adjective, and very occasionally, as a verb.
I suspected that she was from quite a bourgie family, it was only when I found out that her family live in a castle and go grouse hunting at the weekends that I realised that she's actually a fully-fledged crat.
You really should get your hair cut. Only Hugh Grant can pull off such a crat hairstyle.
The tranquil silence that reigns in the office is occasionally broken by the boss noisily cratting about the place in his blue blazer and chinos.
Mark: What a crat!
Jim: Kasey sent back a million revisions to my powerpoint. This is the third time she's reviewed it!
Terrell: You just got cratted on real bad.
I told her it was a very old type of cat known as a "target crat". In a loud and excited voice she proclaimed to her dad and all the other customers "That crat's a target!" I head for the check out counter quietly while the other customers were trying to convince the girl that the cat wasn't a target. She wouldn't believe them and kept yelling "The crats a target! The crat's a target crat. That nice old man told me so!".