The act of emitting intestinal methane gas, i.e., a fart, while underwater, especially in the bathtub, causing the gas to bubble up through the water only to emerge with increased sound and odor as it hits the air. Playing the water trumpet takes on added enjoyment when one positions one's anus so that the emitted gas tickles up one's backside as it rises up through the water.

A phrase to describe someone who is cognitively degenerating. Synonym of "going off the deep end". Can have varying degrees of severity.

Reference to the song "Hey You" by Pink Floyd. The line "and the worms ate into his brain" makes no sense in an otherwise linear and literal narration throughout the lyrics.