Dash back to look at very famous dancer (7)
I believe the answer is:
nureyev
'famous dancer' is the definition.
(I've seen this before)
'dash back to look at very' is the wordplay.
'dash' becomes 'run' (I've seen this before).
'back' says the letters should be written in reverse.
'to look at' becomes 'eye' (I've seen this before).
'very' becomes 'v' (abbreviation).
'run' back-to-front is 'nur'.
'nur'+'eye'+'v'='NUREYEV'
(Other definitions for nureyev that I've seen before include "Fonteyn's dancing partner Rudolf" , "Rudolf -, Russian ballet dancer" , "Who might have danced" , "Austrian ballet dancer, 1938-93" , "Famous Russian ballet dancer" .)