Hi there! It would be great to have the entire sentence, but I'll share what I can here... It happened at the very hour that she won the lottery. Meaning: In the same hour, within the same hour. Hope this helps you! Keep on learning! :) David

Hour here is being used in a slightly old fashioned, but still sometimes used, way to mean the time at which something occurs rather than a period of 60 minutes. Very adds emphasis, this has its usual meaning. Therefore this very hour is an emphatic and poetic way of saying 'now'.

that spesific hour, not before not after but that very hour