Beneath the surface, regressive mongrel ban enrages facilitator (7)
I believe the answer is:
enabler
'facilitator' is the definition.
(I've seen this before)
'beneath the surface regressive mongrel ban enrages' is the wordplay.
'ENABLER' is hidden back-to-front within the letters.
However, I'm unsure how the hidden word is indicated.
Can you help me to learn more?
(Other definitions for enabler that I've seen before include "One who makes possible" , "I give authority" , "Something that makes (action) possible" , "It makes (thing) possible" , "One giving authority" .)