What temperance movement might do for explanation? (9)
I believe the answer is:
rationale
'for explanation?' is the definition.
(rationale is a kind of explanation)
I can't explain the rest of the clue.
(Other definitions for rationale that I've seen before include "Motivation" , "Logical basis (for a course of action)" , "Logical reason for action" , "Logical reasons (for action)" , "grounds?" .)