Easily cowed, I’m alarmed by motorway (4)
I believe the answer is:
meek
'easily cowed' is the definition.
(I've seen this in another clue)
'i'm alarmed by motorway' is the wordplay.
I cannot really understand how this works, but
'i'm' could be 'me' (both refer to the person speaking or writing) and 'me' is present in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for meek that I've seen before include "Humbly compliant" , "Gentle and submissive" , "Gentle, timid" , "Mild and gentle" , "Mild and timid" .)