Don't move SNP supporter, say, occupying platform (8)
I believe the answer is:
stagnate
'don't move' is the definition.
The definition and answer can be both to do with social activities as well as being verbs in their base form.
Maybe there's an association between them I don't understand?
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for stagnate that I've seen before include "Become still and stale, pond or people (8)" , "Cease moving" , "Show little activity" , "Become foul from inertia" , "Cease to flow and become smelly" .)