1. a frankfurter.
2. a sandwich consisting of a frankfurter in a split roll, usually eaten with mustard, sauerkraut, or relish.
3. Also, hotdog, hot dogger, hotdogger, hot-dogger. Informal.
a. a person who performs complex, showy, and sometimes dangerous maneuvers, esp. in surfing or skiing.
b. a show-off, esp. in sports.
4. Informal. (used to express great joy or delight.)