E. Cobham Brewer 1810–1897. Dictionary of Phrase and Fable. 1898.
Round Sum.
A good round sum. A large sum of money. Shakespeare says the Justice has a “big round belly, with good capon lined;” and the notion of puffed out or bloated is evidently the idea of Shylock when he says to Bassa’nio, “’Tis a good round sum.”
