Rules about small leaves work (7)
I believe the answer is:
resigns
'leaves work' is the definition.
The definition and answer can be both related to thinking as well as being verbs in their -s form.
Maybe you can see a link between them that I don't see?
'rules about small' is the wordplay.
'rules' becomes 'reigns' (reign can mean to rule or govern).
'about' is an insertion indicator.
'small' becomes 's' (abbreviation - e.g. clothes size).
'reigns' placed around 's' is 'RESIGNS'.
Can you help me to learn more?
(Other definitions for resigns that I've seen before include "does the honourable thing" , "abdicates" , "Leaves job voluntarily" , "Gives up (a post)" .)