Similar to a brainer when smoking a joint, you put a joint in your ass and fart a nasty brainer into another person's mouth. That person will be on their knees accepting the brainer, in a praying position. While pinching the joint in the ass, it's guaranteed to make a high pitched horn sound. Hence, a Holy Trumpet.
She blew the nastiest Holy Trumpet the other night. Knocked me on my ass so hard I got religious for a minute.
by Dean Modified October 02, 2014