What is gossip?

"They were filled with all manner of unrighteousness, evil, covetousness, malice. They are full of envy, murder, strife, deceit, maliciousness. They are gossips," (Romans 1:29, ESV)

"For I fear that perhaps when I come I may find you not as I wish, and that you may find me not as you wish—that perhaps there may be quarreling, jealousy, anger, hostility, slander, gossip, conceit, and disorder." (2 Corinthians 12:20, ESV)

"Besides that, they learn to be idlers, going about from house to house, and not only idlers, but also gossips and busybodies, saying what they should not." (1 Timothy 5:13, ESV)

How would you define gossip? Recently I heard these definitions of gossip:

1. Gloating over the shortcomings and the sins of others
2. Passing on to others unfavorable truth that is unnecessary for others to know
3. Enjoying vice vicariously

Gossip is one of the most rampant and most respectable sins today. People even publish gossip columns and they are read by millions of people.

Notice that gossip can even be something true. We often equate "gossip" and "rumors", but they are not equal. If you pass on unfavorable truth to others who don't need to know, that is gossip.
What do you think? How would you define gossip?