Like to be in bed, it's established (5)
I believe the answer is:
based
'established' is the definition.
('base' can be a synonym of 'establish')
'like to be in bed' is the wordplay.
'like' becomes 'as'.
'to be in' indicates putting letters inside.
'as' put into 'bed' is 'BASED'.
'it's' is the link.
(Other definitions for based that I've seen before include "Founded, grounded" , "Founded or used as evidence" , "Positioned" , "(Of aircraft) stationed" , "Located" .)