Reportedly instructed to be tense (4)
I believe the answer is:
taut
'be tense' is the definition.
(similar in meaning)
'reportedly instructed' is the wordplay.
'reportedly' indicates a 'sounds like' (homophone) clue.
'instructed' becomes 'taught' ('teach' can be a synonym of 'instruct').
'taught' sounds like 'TAUT'.
'to' is the link.
(Other definitions for taut that I've seen before include "Pulled or drawn tight" , "Stretched, pulled tight" , "Tense, stretched tight" , "seaworthy" , "Tightly drawn" .)