What is Boshetunmai?
1.
An adjective. A slang word for use in place of such words as "cool", "awesome", "crazy!", "evil!", "great!", "rad!", "Viktor-Tsoy-related!", etc.
The Crazy Sushi forums are so boshetunmai!
2.
other variants may include
"be worthy" or "don't sell yourself"
(reported to be translations from Mongolian and Korean)
"Boshetunmai!" can be used alone