Dance item possibly a strain for dance specialist (6-8)

'dance specialist' is the definition.
The definition suggests a singular noun which matches the answer.

'dance item possibly a strain' is the wordplay.
'dance' becomes 'ball' (ball is a kind of dance).
'possibly' indicates anagramming the letters.
'a strain' becomes 'stress' ('stress' can be a synonym of 'strain').
'item' with letters rearranged gives 'etmi'.
'ball'+'etmi'+'stress'='BALLET-MISTRESS'

'for' is the link.