Beaten on board (5)
I believe the answer is:
mated
'beaten on board' is the definition.
The answer and definition can be both to do with contact as well as being past participle verbs.
Perhaps there's an association between them I don't understand?
'on board' is the wordplay.
I cannot quite understand how this works, but
'on' could be 'at' (I've seen this in other clues) and 'at' is found within the answer.
The remaining letters 'med' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for mated that I've seen before include "given match" , "Defeated in game" , "Joined, connected" , "had sex" .)
