A hot dog (also called franks) was a Human food from Earth, made popular in the 20th century. They were a type of sausage-based snack, particularly associated with being a snack food for spectators during baseball games.
Roy Ritterhouse claimed in 1953, he had had extra sauerkraut on his franks the night before when the writers of Incredible Tales complained about a drawing he had made of a bug-eyed monster climbing a building. (DS9: "Far Beyond the Stars")
While on 1996 Earth, Tuvok got footlong hot dogs, chili burritos and Goliath gulps for himself, Tom Paris and Rain Robinson for breakfast one morning. Robinson likened the meal to something she would expect to eat on an afternoon at Dodger Stadium. (VOY: "Future's End, Part II") The Hot Dog on a Stick, a 20th century establishment in Los Angeles, specialized in selling hot dogs and fresh lemonade. (VOY: "Future's End, Part II")
Kira Nerys was confused by the food's name in 2372, which outside of its direct meaning implies a heated canine, when Benjamin Sisko promised to treat her to the snack while the two watched a holodeck simulation of a baseball game. (DS9: "Starship Down")