輪

Phono-semantic compound:

車 (수레 차, “cart, vehicle”) — semantic, referring to vehicles/wheels.

侖 (생각할 륜, “order, arrangement”) — phonetic, providing sound.

Thus 輪 originally signified “the wheel of a cart”, and by extension came to mean “anything circular, a round, rotation, sequence.”

車輪 (차륜) — wheel of a vehicle

輪廻 (윤회) — cycle of rebirth, samsara

年輪 (연륜) — annual growth rings in trees; life experience

齒輪 (치륜) — gearwheel, cog

一輪 (일륜) — one round, a disk (often the sun or moon)

In Buddhist terminology, 輪 often means “wheel of Dharma” (法輪).