rattle away
To speak tediously and at great length (about something). He just kept rattling away about literary metaphors and imagery. I didn't know what he was talking about! I caught myself starting to fall asleep while the professor rattled away.
rattle away
to chatter endlessly and aimlessly. The two old men sat there and rattled away at one another. Tom rattled away at Jane for a few minutes and then left the house.