Perform with a mix of tailless cats (3)
I believe the answer is:
act
'perform' is the definition.
(acting is a kind of performing)
'mix of tailless cats' is the wordplay.
'mix of' indicates anagramming the letters.
'tailless' means to remove the last letter (the tail of the word is removed).
'cats' with its last letter removed is 'cat'.
'cat' anagrammed gives 'ACT'.
'with a' acts as a link.
(Other definitions for act that I've seen before include "Assumed attitude" , "Take steps" , "Behave like thespian" , "Accomplishment" , "Bill successfully prosecuted" .)