Nonsense from scoundrel drinking gallons - occasionally showing beer belly (8)
I believe the answer is:
'nonsense' is the definition.
(I've seen this before)
'scoundrel drinking gallons occasionally showing beer belly' is the wordplay.
I cannot quite understand how this works, but
'scoundrel' could be 'dog' (dog is a kind of scoundrel) and 'dog' is found within the answer.
'gallons' could be 'g' (abbreviation) and 'g' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
'from' acts as a link.
Can you help me to learn more?
(Other definitions for doggerel that I've seen before include "Very bad poetry or verse" , "William McGonagall's kind of poetry?" , "Rubbishy verse" , "Worthless verse - gored leg (anag)" , "questionable verse" .)