triad

中文： 三合会、黑社会、三和弦

1. A grouping of three.
2. A romantic or sexual relationship between three individuals; a throuple.
3. A word of three syllables.
4. A branch of a Chinese underground criminal society, mostly based in Hong Kong.
5. On a CRT display, a group of three neighbouring phosphor dots, coloured green, red, and blue.
6. A chord consisting of a root tone, the tone two degrees higher, and the tone four degrees higher in a given scale OR any chord with three notes.

复数 triads