Follower provides commercial gas lease (8)
I believe the answer is:
adherent
'follower' is the definition.
(I know that adherent is a type of follower)
'commercial gas lease' is the wordplay.
'commercial' becomes 'ad' (abbreviation for advertisement).
'gas' becomes 'He' (chemical symbol for helium).
'lease' becomes 'rent' (synonyms).
'ad'+'he'+'rent'='ADHERENT'
'provides' is the link.
(Other definitions for adherent that I've seen before include "Devotee" , "Weep" , "sticker" , "Staunch follower" , "Loyal follower, one who sticks" .)