Speech lacking commercial cover (5)
I believe the answer is:
dress
'cover' is the definition.
(I know that cover is a more specific form of the action dress)
'speech lacking commercial' is the wordplay.
'speech' becomes 'address' (synonyms).
'lacking' suggests deleting specific letters.
'commercial' becomes 'ad' (abbreviation for advertisement).
'address' with 'ad' removed is 'DRESS'.
(Other definitions for dress that I've seen before include "Treat" , "Gown" , "female garment" , "clean > bandage" , "Cultivate < tidy" .)