Instructed in pronunciation of tense (6)
I believe the answer is:
taught
'instructed' is the definition.
('teach' can be a synonym of 'instruct')
'pronunciation of tense' is the wordplay.
'pronunciation of' shows a homophone (sound like).
'tense' becomes 'taut' ('taut' can be similar in meaning to 'tense').
'taut' sounds like 'TAUGHT'.
'in' acts as a link.
(Other definitions for taught that I've seen before include "Tutored" , "disciplined" , "Educated" , "as a pupil" , "given a lesson" .)