About to damage amulet (5)
I believe the answer is:
charm
'amulet' is the definition.
('charm' can be a synonym of 'amulet')
'about to damage' is the wordplay.
'about' becomes 'c' (abbreviation for 'circa').
'to damage' becomes 'harm' ('harm' can be a synonym of 'damage'**).
'c'+'harm'='CHARM'
(Other definitions for charm that I've seen before include "Lure" , "pleasing feature" , "Engaging quality" , "a delightful feature" , "Power of fascination" .)