Less worried about total burdens (7)
I believe the answer is:
saddles
'burdens' is the definition.
('saddle' can be a synonym of 'burden')
'less worried about total' is the wordplay.
'worried' indicates an anagram.
'about' means one lot of letters goes inside another.
'total' becomes 'add' ('add' can be a synonym of 'total').
'less' is an anagram of 'sles'.
'sles' enclosing 'add' is 'SADDLES'.
(Other definitions for saddles that I've seen before include "Seats for horses" , "Jockeys' seats" , "Riding seats" , "These joints of meat" , "Burdens" .)