1A mum ran upstairs, about to confiscate a weapon (5)
I believe the answer is:
unarm
'to confiscate a weapon' is the definition.
(remove a weapon from someone)
'1a mum ran upstairs' is the wordplay.
'mum ran' can be anagrammed to 'UNARM'.
Though, I'm unsure how the anagram is indicated.
'about' is the link.
Can you help me to learn more?
(Other definitions for unarm that I've seen before include "Remove weaponry from" , "Take weapons from (someone)" , "Take weapon" , "Remove firing pieces" , "Remove weapons from" .)