"Gat the horn" is a phrase often used in Scotland that means to become angry or agitated. There are many synonyms for this phrase, including "get hot under the collar," "blow a gasket," "lose one's cool," and "fly off the handle." All of these phrases refer to the same general idea of becoming upset or angry. Other phrases include "go ballistic," "fume," "spit nails," and "steam." When someone is experiencing this type of emotion, it is important to try and remain calm and not let the situation escalate. It is also important to find healthy ways to manage and express one's emotions.