Disturbances on the radio, still (6)
I believe the answer is:
static
I believe this is a double definition.
'disturbances on the radio' is the first definition.
(radio static)
'still' is the second definition.
(static can mean still or not moving)
(Other definitions for static that I've seen before include "Crackling or hissing noise caused by electrical interference" , "Inactive or inert" , "Inert or passive, like some electricity" , "it can shock and > ruin the reception" , "Stationary" .)