A false move is said to be lacking courage (5)
I believe the answer is:
feint
'a false move' is the definition.
(I've seen this in another clue)
'said to be lacking courage' is the wordplay.
'said to be' indicates a 'sounds like' (homophone) clue.
'lacking courage' becomes 'faint' (I've seen this in another clue).
'faint' is a homophone of 'FEINT'.
'is' is the link.
(Other definitions for feint that I've seen before include "Deceptive movement designed to distract" , "(Make a) deceptive move" , "Deceptive manoeuvre" , "Misleading action" , "Deceptive motion" .)