Passive (5)
I believe the answer is:
inert
'passive' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for inert that I've seen before include "Indolent - unreactive" , "Unreactive; still" , "Without the strength to move" , "Like e.g. xenon" , "Sluggish, still" .)