RhymeZone: red dog definitions

Definitions of red dog:

noun: (countable, US, American football) A blitz.
noun: (uncountable) The lowest grade of flour in milling, secured largely from the germ or embryo and adjacent parts, and mainly useful as animal feed.
noun: (uncountable) Coal slag.
noun: (uncountable, informal) Prickly heat; miliaria.
noun: Used other than figuratively or idiomatically: see red, dog.
verb: (US, American football) To blitz.
noun: A card game in which players bet on the next card to appear.

(Definitions from Wiktionary)