Move off directly (4-2)
I believe the answer is:
head-on
'directly' is the definition.
(synonyms)
'move off' is the wordplay.
I cannot quite see how this works, but
'move' could be 'ado' (ado is a kind of move) and 'ado' is present in the answer.
The remaining letters 'hen' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for head-on that I've seen before include "In direct confrontation" , "(Of crash) involving the front of vehicle)" , "One had (anag.)" , "In direct opposition" , "This collision is full frontal" .)