"Big Daddy" Brotherson, upon scrutiny, has a threefold recurrence of a familial theme-- "daddy", "brother," and "son" all are familial terms, "daddy" the paternal figure, "brother" the fraternal, and "son" the filial. This analysis is unlikely to be mistaken. The "big" is likely a somewhat prosaic intensifier to denote the fact "Big Daddy" Brotherson is, indeed, big, or, when fluxed with its adjacent "Daddy," it forms "Big Daddy," an informal title which is idiomatic of power or paternalism.
Confidence: 90