Broadcast about launch of canal boat (4)
I believe the answer is:
scow
'boat' is the definition.
(I know that scow is a type of boat)
'broadcast about launch of canal' is the wordplay.
I cannot really understand how this works, but
'about' could be 'c' (circa) and 'c' is present in the answer.
'broadcast' could be 'sow' (sowing is a kind of broadcasting) and 'sow' is found in the leftover letters.
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 scow that I've seen before include "ighter" , "Flat-bottomed boat for cows" , "Vessel" , "Wide-beamed dinghy" , "Maybe lighter" .)