Still concealed in attics? (6)
I believe the answer is:
static
'still' is the definition.
(static can mean still or not moving)
'concealed in attics?' is the wordplay.
'concealed in' indicates an anagram.
'attics' is an anagram of 'STATIC'.
(Other definitions for static that I've seen before include "Not active or moving" , "Not moving or changing" , "disturbing thing" , "Crackling or hissing noise caused by electrical interference" , "Stationary" .)