Feverishly seek term about universal soldier (9)
I believe the answer is:
musketeer
'soldier' is the definition.
(musketeer is a kind of soldier)
'feverishly seek term about universal' is the wordplay.
'feverishly' is an anagram indicator (feverish can mean wild or agitated).
'about' indicates putting letters inside.
'universal' becomes 'u'.
'seek'+'term'='seekterm'
'seekterm' is an anagram of 'msketeer'.
'msketeer' going around 'u' is 'MUSKETEER'.
(Other definitions for musketeer that I've seen before include "Athos perhaps" , "one of three likely to?" , "Old soldier with shoulder gun with a long barrel" , "Former soldier" , "Historical soldier" .)