One's little mate with a place across the road (8)
I believe the answer is:
opposite
'one's little' is the definition.
Both the answer and definition are adjectives. Perhaps there's an association between them I don't understand?
'mate with a place across the road' is the wordplay.
I cannot quite see how this works, but
'mate' could be 'oppo' (I've seen this before) and 'oppo' is found in the answer.
'place' could be 'site' (synonyms) and 'site' is found in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for opposite that I've seen before include "Facing - reverse" , "Adverse" , "Directly facing each other" , "Contary of face-to-face" , "Antithetical, vis-a-vis at" .)