Cheers that man, earlier sad, starting to brood (4,3,5)
I believe the answer is:
down the hatch
'cheers' is the definition.
(I've seen this before)
'man earlier sad starting to brood' is the wordplay.
I cannot quite understand how this works, but
'man' could be 'he' (he refers to a man) and 'he' is present in the answer.
'sad' could be 'down' (down can mean sad or unhappy) and 'down' is found in the answer.
'brood' could be 'hatch' (synonyms) and 'hatch' is found in the answer.
A single letter 't' remains which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'that' acts as a link.
Can you help me to learn more?
(Other definitions for down the hatch that I've seen before include "below deck? - with 9a" , "evokes cheers" , "(As a toast) drink up!" .)