Strong odour alerts ten charge nurses (6)
I believe the answer is:
stench
'strong odour' is the definition.
(stench can mean a strong smell)
'alerts ten charge nurses' is the wordplay.
'nurses' says the answer is hidden in the clue (nurse can mean holding closely).
'STENCH' can be found hidden inside 'alerts ten charge'.
(Other definitions for stench that I've seen before include "Stink" , "A really vile smell" , "Awful pong" , "Miasma" , "Evidence of corruption" .)