Set (in) (5)
'set in' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for embed that I've seen before include "Fix firmly (in ground)" , "Fix fast in something solid" , "Put entirely inside something else" , "war reporter" , "bringing plant inside" .)
(Other definitions for based that I've seen before include "Worthless" , "Founded or used as evidence" , "Founded, grounded" , "(Of aircraft) stationed" , "Stationed (in a place)" .)