The words "gat horn" do not have any direct antonyms, as they are not commonly used terms. However, "gat" can refer to a firearm or gun, in which case, antonyms such as "peace," "love," "harmony," or "nonviolence" could be considered. "Horn" can refer to a musical instrument, and antonyms for this meaning could include "silence" or "quiet." It is important to note that the word "gat horn" together has a very specific meaning, and thus, the concept of antonyms for it may not be applicable in the same way as more commonly used terms.