More in base worried (8)
I believe the answer is:
bothered
'worried' is the definition.
(thesaurus)
'more in base' is the wordplay.
'more' becomes 'other' ('other' can be a synonym of 'more').
'in' means one lot of letters goes inside another.
'base' becomes 'bed' (bed is a kind of base).
'other' placed within 'bed' is 'BOTHERED'.
(Other definitions for bothered that I've seen before include "Was a pest" , "''Bewitched, ... and bewildered'' (song) (8)" , "Took the trouble to do something" , "The bored, strangely, can be troubled" , "Disturbed" .)