rave
[WPI] vi. 1. To persist in discussing a specific subject.
2. To speak authoritatively on a subject about which one knows
very little. 3. To complain to a person who is not in a position
to correct the difficulty. 4. To purposely annoy another person
verbally. 5. To evangelize. See flame. 6. Also used to
describe a less negative form of blather, such as friendly
bullshitting. `Rave' differs slightly from flame in that
`rave' implies that it is the persistence or obliviousness of the
person speaking that is annoying, while flame implies somewhat
more strongly that the tone or content is offensive as well.