1. Describes the sound made by a trombone to illustrate a depressing statement, action, or moment. "Wah waah". Pioneered on the SNL skit Debbie Downer.
Bjorn: I don't think so. Nell, would you like to see the pictures I have of Sir Fluffles?
Nell: Oh, Bjorn, I can't bear to look at pictures of cats -- they only make me think of watching my own Mr. Snowflake waste away due to the effects of Feline Leukemia.
Tad: Wow... sad trombone!
K-rad was made popular in the 1980s by computer hacker circles. The word 'rad' reffered to a radical act performed by a hacker which deserved congratulations.
The term k-rad originated around the same time people started talking in numbers l1k3 th15. This type of language first started apearing on BBSes and FTP warez sites.
(I have the most leet, k-rad skillz on the net!)