Giant struggle for breath over a thin porridge (10)

'giant' is the definition.
Both the definition and answer are singular nouns.
Perhaps there's an association between them I don't understand?

'struggle for breath over a thin porridge' is the wordplay.
'struggle for breath' becomes 'pant' (to pant is to struggle for breath).
'over' says to put letters next to each other (in a down clue, some letters go over others).
'thin porridge' becomes 'gruel' (I've seen this in another clue).
'pant'+'a'+'gruel'='PANTAGRUEL'

Can you help me to learn more?