swooning

(verb) pass out from weakness, physical or emotional distress due to a loss of blood supply to the brain. Synonyms: faint, conk, swoon, pass out.

(adj) weak and likely to lose consciousness. Synonyms: faint, light, light-headed, lightheaded. Examples: "Suddenly felt faint from the pain." "Was sick and faint from hunger." "Felt light in the head." "A swooning fit." "Light-headed with wine." "Light-headed from lack of sleep."