While soft, it's dangerous (3)
I believe the answer is:
asp
'it's dangerous' is the definition.
I can't tell whether this defines the answer.
'while soft' is the wordplay.
'while' becomes 'as'.
'soft' becomes 'p' (musical abbreviation for 'piano').
'as'+'p'='ASP'
Can you help me to learn more?
(Other definitions for asp that I've seen before include "It proved deadly for Cleopatra" , "Snake found in spa" , "Cleopatra-killing snake" , "creeper" , "Cleopatra's poisoner" .)