The word "玄机" is formed by combining the character "玄", meaning mysterious or profound, which originates from pictographic representations of darkness or obscurity, with the character "机", meaning mechanism or principle, which is a phono-semantic compound consisting of the semantic radical "木" (wood) and the phonetic component "几". Together, they create a compound noun where "玄" modifies "机" to denote a hidden mechanism or esoteric truth.