Meat a dog has taken aboard (6)
I believe the answer is:
mutton
'meat' is the definition.
(I know that mutton is a type of meat)
'a dog has taken aboard' is the wordplay.
I cannot really see how this works, but
'dog' could be 'mutt' (mutt is a kind of dog) and 'mutt' is found in the answer.
'aboard' could be 'on' (eg on a ship or train) and 'on' 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 mutton that I've seen before include "Sheep as food" , "Flesh of sheep" , "can be eaten" , "Sheep's meat" , "Sheep's flesh" .)