Slang for gossip or a rumor. This is an old naval term. Literally, the "scuttlebutt" was a canteen or barrel of fresh water (nowadays a drinking fountain) on a ship, around which sailors would gather to exchange the day's news.

For example:

When the CEO left, the rumors started flying. The scuttlebutt was that his wife caught him "digging in the corporate mine", if you know what I mean.