Beatnik, he trips out (7)
I believe the answer is:
hipster
'beatnik' is the definition.
(I've seen this in another clue)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for hipster that I've seen before include "Trendsetter" , "fitting below the waist" , "Dedicated follower of fashion" , "Follower of the latest fashions" , "Trendy person" .)