The term 'gat beam' is a niche architectural term used to describe the horizontal wooden beam that rests on the two vertical posts of a gate frame. However, there are several other words and phrases that can be used interchangeably with 'gat beam'. These include gate header, gate crossbeam, gate lintel, gate sill, and gate sill plate. These synonyms come in handy when communicating with non-architecture professionals or when trying to explain complex designs in simpler, more generic terms. Regardless of the synonym, the gat beam serves the same purpose; supporting the weight of the gate and transferring it to the support posts.