Round leader in parliament, Charles I scattered guards (9)
I believe the answer is:
spherical
'round' is the definition.
('spherical' can be similar in meaning to 'round')
'leader in parliament charles i scattered guards' is the wordplay.
'leader in' indicates taking the first letters.
'scattered' is an anagram indicator.
'guards' indicates putting letters inside.
The initial letter of 'parliament' is 'p'.
'charles'+'i'='charlesi'
'charlesi' anagrammed gives 'sherical'.
'p' placed inside 'sherical' is 'SPHERICAL'.
(Other definitions for spherical that I've seen before include "Globe-shaped" , "Rotund" , "Ball-shaped" , "Completely round" , "Like a ball" .)