Syzygy (Spelled 'sizijē)
means a conjunction or opposition, especially of the moon with the sun. It could also describe the pairing/union of two similar yet subtly opposite things coming together.

If you know of Liu Cixin's 3 body problem, the example  phenomenon in the Netflix adaptation show a Tri-solar alignment which occurs during the chaotic era in the planet of the San-Ti Ren (aliens).