noun, noun or participle which takes 'suru', intransitive verb
fainting in agony; writhing in pain
Describes losing consciousness or being overwhelmed by extreme pain, pleasure, or other intense sensation. Often used in dramatic or humorous contexts.
あまりの痛さに悶絶した。
I fainted from the unbearable pain.
そのギャグに悶絶するほど笑った。
I laughed so hard at the gag that I nearly passed out.
Standard kanji spelling.
気絶 is a general term for fainting or losing consciousness, while 悶絶 specifically implies fainting from agony or intense sensation.
Compound of 悶 (agony, anguish) and 絶 (to cease, to cut off). The exact historical derivation is uncertain, but the combination conveys the idea of being overwhelmed to the point of losing consciousness.