Speech giving notice to groom? (7)
I believe the answer is:
address
'speech' is the definition.
('address' can be a synonym of 'speech')
'giving notice to groom?' is the wordplay.
'giving' means one lot of letters go next to another.
'notice' becomes 'ad'.
'to groom?' becomes 'dress' (dressing is a kind of grooming**).
'ad' put next to 'dress' is 'ADDRESS'.
(Other definitions for address that I've seen before include "Think about" , "Treat" , "One's postal residence." , "details on envelope" , "Call" .)