Changed course, reportedly, showing diplomacy (4)
I believe the answer is:
tact
'diplomacy' is the definition.
(thesaurus)
'changed course reportedly' is the wordplay.
'changed course' becomes 'tacked' (I've seen this before).
'reportedly' indicates a 'sounds like' (homophone) clue.
'tacked' sounds like 'TACT'.
'showing' acts as a link.
(Other definitions for tact that I've seen before include "Skill in dealing with people" , "Delicacy of feeling, skill in saying the right thing" , "Diplomatic skill" , "Sensitivity, diplomacy" , "measure of diplomacy?" .)