Unease (12)
'unease' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for restlessness that I've seen before include "Inability to keep still" , "Agitation" , "Quality involving constant activity" , "Unease" , "Inability to relax -- lessen stress (anag)" .)
'unease' is the definition.
(I have seen 'Morbid unease ' mean 'anxiety' so perhaps 'unease' could also mean 'anxiety')
This is all the clue.
(Other definitions for anxiety that I've seen before include "Uneasiness, worry" , "Morbid unease" , "Disquiet" , "Worry, concern" , "tension" .)