Instructed (6)
'instructed' is the definition.
(synonyms)
This is all the clue.
(Other definitions for taught that I've seen before include "Imparted skills or knowledge to" , "Instructed, schooled" , "Educated" , "Was a teacher" , "given a lesson" .)
'instructed' is the definition.
(briefing is a kind of instructing)
This is all the clue.
(Other definitions for briefed that I've seen before include "Instructed in advance" , "Advised or instructed, like barrister" , "Prepared" , "Informed of the facts" .)
'instructed' is the definition.
(both can mean taught)
This is all the clue.
(Other definitions for tutored that I've seen before include "Was coach" , "Gave private lessons to" , "Taught small groups" , "Rude tot (anag.)" , "Privately taught" .)