The word 窍门 is formed by combining the character 窍, which means "aperture" or "key point" and is composed of the radical 穴 (indicating a cave or hole) and the phonetic component 巧 (providing the sound qiǎo), with the character 门, meaning "door" or "gate". Together, they create a compound where the literal idea of a "door's keyhole" is used metaphorically to represent a clever method or knack for achieving something.