Inactive, motionless (6)
I believe the answer is:
static
I believe this is a double definition.
'inactive' is the first definition.
(I know that inactive can be written as static)
'motionless' is the second definition.
(I know that motionless can be written as static)
(Other definitions for static that I've seen before include "Steady" , "Unmoving like kind of electricity" , "Still - type of electricity" , "Changeless" , "Atmospheric disturbance" .)