Tumbler that's black, held by a European (7)
I believe the answer is:
acrobat
'tumbler' is the definition.
(synonyms)
'black held by a european' is the wordplay.
'black' becomes 'b' (abbreviation as in pencil hardness).
'held by' indicates putting letters inside.
'european' becomes 'croat' (person from Croatia).
'a'+'croat'='acroat'
'b' placed within 'acroat' is 'ACROBAT'.
'that's' is the link.
(Other definitions for acrobat that I've seen before include "Performing gymnast" , "Athletic Circus Performer" , "User of five ac" , "Circus star" , "Gymnastic entertainer" .)