I went to see Shakespeare's The Comedy of Errors at the National Theatre last night, and noticed that the final scene contains lots of instances of the word 'gossip' in different forms:
"Go to a gossips' feast and go with me"
"With all my heart, I'll gossip at this feast"
"Will you walk in to see their gossiping?"
Gossip in these senses means "take part in a feast" and a gossiping is a "merry-making". The original meaning of the verb to gossip was 'to sponsor at a baptism'. The earliest citation for this sense is 1616, and is again from Shakespeare, although this time All's Well That Ends Well. The noun 'gossip' (original meaning 'godfather or godmother, baptismal sponsor) is much older -- the first citation in the OED is dated 1014. The word has an Old English root and is made up of god + sib (= related, cf the modern 'sibling'). In the 14th century the word came to mean 'friends or chums', and a couple of hundred years later it especially referred to a woman's friends who helped out while she was giving birth.
Once the word began referring to women, it didn't take long for the meaning of the word to pejorate to "A person, mostly a woman, of light and trifling character, esp. one who delights in idle talk; a newsmonger, a tattler" (from OED). Only in the early 19th century did the talk itself begin to be described as 'gossip' as well as the people doing the talking.