Member, one's slow to pass law (9)
I believe the answer is:
legislate
'pass law' is the definition.
(I've seen this before)
'member one's slow' is the wordplay.
'member' becomes 'leg' (I've seen this before).
'one's' becomes 'is' (roman numeral).
'slow' becomes 'late' (I've seen this in other clues).
'leg'+'is'+'late'='LEGISLATE'
'to' is the link.
(Other definitions for legislate that I've seen before include "put in force" , "For what governments do" , "Make provision" , "Make a ruling" , "Pass through the house" .)