The phrase "gat on horn" has an interesting spelling. The word "gat" is spelled like "cat" with the initial "c" replaced by a "g". It is pronounced /ɡæt/. The word "on" is spelled regularly, pronounced /ɒn/. Finally, the word "horn" is spelled like it sounds, but with an additional "r" at the end, pronounced /hɔːrn/. This phrase is often used in the context of hunting, referring to the idea of a hunter carrying a shotgun while riding on horseback.