Permit required for Gaelic ensemble (7)
I believe the answer is:
license
'permit' is the definition.
(I know that permit can be written as license)
'required for gaelic ensemble' is the wordplay.
'required for' says the answer is hidden in the clue.
'LICENSE' can be found hidden inside 'gaelic ensemble'.
(Other definitions for license that I've seen before include "Authorise officially" , "Allow" , "Grant official permit to sell or trade" , "Silence (anag.)" , "Grant formal permission (to)" .)