Gymnast that can be found on a bar? (7)

I believe the answer is:
tumbler
'gymnast' is the definition.
(tumbler is a kind of gymnast)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for tumbler that I've seen before include "might be full of drink" , "Constantly dropping" , "Stemless straight-sided glass" , "One flips" , "Machine for drying" .)
