also hotdog, "sausage on a split roll," c.1890, popularized by cartoonist T.A. Dorgan. It is said to echo a 19c. suspicion (occasionally justified) that sausages contained dog meat. Meaning "someone particularly skilled or excellent" (with overtones of showing off) is from 1896. Connection between the two senses, if any, is unclear. Hot dog! as an exclamation of approval was in use by 1906.
An exclamation of delight, gratification, relish, etc; hot damn, hot shit: Did you have a good time? ''Hot dog!'' (1906+)
modifier: Walter is one of the good guys, not a hot dog (1966+)
verb phrasehighly seasoned sausage, traditionally of mixed pork and beef. Frankfurters are named for Frankfurt am Main, Ger., the city of their origin, where they were sold and eaten at beer gardens.