Definition: <b>Trigate</b><br> When used to describe a political item such as a button or pin, Trigate refers to three images on a pin. For instance a trigate might have both the presidential and vice-presidential candidates pictured. <p> According to the <a href="http://apic.us/">American Political Items Collectors</a> trigate images are also found on posters, pennants, postcards and other forms of campaign items.