Change course or change sides, embracing the left (7)
I believe the answer is:
deflect
'change course' is the definition.
(I've seen this before)
'change sides embracing the left' is the wordplay.
'change sides' becomes 'defect' (I've seen this before).
'embracing' means one lot of letters goes inside another.
'the left' becomes 'L' (common abbreviation).
'defect' placed around 'l' is 'DEFLECT'.
'or' is the link.
(Other definitions for deflect that I've seen before include "Cause to go off course" , "Swerve" , "Turn from straight course" , "Turn aside from an intended course" , "change direction" .)