Fainting, in a swoon. Originally and chiefly in predicative use with fall.

Bereft of sensation or vitality; benumbed, insensible. Of persons: deathlike, insensible, in a swoon. Obsolete. Also of sleep, a faint.

passive. To fall into a swoon; chiefly past participle or participial adjective: In a swoon.

(also attributive).

Failing, fainting; of or pertaining to swooning. Obsolete.

In a trance; entranced. Also figurative.

That swoons; swooning.

That swoons or faints; characterized by swooning.

Fallen into a swoon. rare.

Originally U.S. to go out like a light: to lose consciousness instantly; to faint or (now usually) go to sleep; (occasionally also) to die…