惱

A phono-semantic compound composed of:

心 — semantic component meaning “heart; emotions”; 𡿺 — phonetic component indicating the sound (뇌 / nǎo). The character originally described emotional disturbance or distress arising in the heart.
Semantic development: - emotional disturbance; - worry or mental distress; - deep anguish or torment.

번뇌 (煩惱) — mental suffering; worldly afflictions (Buddhist term)

고뇌 (苦惱) — anguish; agony

번뇌하다 — to suffer from worries

Related characters: 心 — heart; mind

悔 — regret

憂 — worry

愁 — sorrow These characters are related to emotional states and mental suffering.
The compound 煩惱 (번뇌) is an important concept in Buddhist philosophy, referring to mental afflictions that cause suffering.