One who gossips, often for the sake of attention.
One who tattles (reports others' wrongdoings), often a child seeking attention.
To act as a tattletale; to tell on; to give away, reveal, or expose.
telltale; giveaway
A person who provides tips or advice to others, for example on the form of racehorses or the stock market.
One who provides tips or hints on how to succeed at a game.