Gírias (K) Slang

K (k): a thousand.
"I could retire with 100 K (k)!"

kick back: relax and enjoy.
"I wish I could kick back at the beach today."

kick off: die.
"My dog finally kicked off."

killer: something exceptional or great.
"Wow, your boyfriend is killer!"

knock: condemn.
"Don't knock it unless you've tried it."

knockout: beautiful woman; handsome man.
"Benjamin is already a knockout!"

kook: peculiar person.
"Stop acting like a kook!"


Source: http://www.eslcafe.com/slang/k.html