faint verb definition in Being ill topic from the Oxford Advanced Learner's Dictionary

faint

 verb: Being ill topic
[intransitive] to become unconscious when not enough blood is going to your brain, usually because of the heat, a shock, etc. to faint from hunger Suddenly the woman in front of me fainted. I'm nearly fainting with the heat in here. (informal) I almost fainted (= I was very surprised) when she told me.