Incantation when source of danger loses power (6)
I believe the answer is:
mantra
'incantation' is the definition.
(I've seen this before)
'source of danger loses power' is the wordplay.
'source of' becomes 'man' (I am not sure about this - if you are sure you should believe this answer much more).
'danger' becomes 'trap' (I have seen 'Hidden danger' mean 'trap' so perhaps 'danger' could also mean 'trap').
'loses' suggests deleting specific letters.
'power' becomes 'p'.
'trap' with 'p' taken away is 'tra'.
'man'+'tra'='MANTRA'
'when' acts as a link.
Can you help me to learn more?
(Other definitions for mantra that I've seen before include "Words repeated as an aid to meditation" , "Hindu word or phrase as aid to meditation" , "Special word or phrase used in Buddhist meditation" , "Watchword" , "Slogan; refrain" .)