1. (noun) When some loud-mouth learns about a secret and tells anyone who will listen.
2. (noun) More specifically, when someone ruins a surprise.
1. Guy: Deina told me that you're cheating on your boyfriend
Girl: Goddamnit! She is such a Paul Revere.
2. Stefan's friends: Surprise, Stefan!!!
Stefan: Sorry guys. Ashley told me about the birthday party. I didn't ask her to pull a Paul Revere, but some people just want to have something to talk about.