Sagacious, almost civil and in charge (7)
I believe the answer is:
politic
'sagacious' is the definition.
('politic' can be similar in meaning to 'sagacious')
'almost civil and in charge' is the wordplay.
'almost' means to remove the last letter (most of the word but not all of it).
'civil' becomes 'polite' ('polite' can be a synonym of 'civil').
'and' says to put letters next to each other.
'in charge' becomes 'ic'.
'polite' with its last letter taken off is 'polit'.
'polit'+'ic'='POLITIC'
(Other definitions for politic that I've seen before include "Prudent, judicious" , "Prudent and tactful" , "artful" , "Wise, cautious" , "Expedient" .)