1) Blab 2) Blabber 3) Blabbermouth 4) Informer 5) Namer 6) Snitch 7) Talebearer 8) Taleteller 9) Tattler 1) Blabbermouth 2) Brown-noser 3) Gossip 4) Gossiper 5) Gossipmonger 6) Kindergarten stoolie 7) Newsmonger 8) One who gives things away 9) Revealing 10) Rumormonger 11) Rumourmonger 12) Schoolroom stoolie 13) Scorned kid brother 14) Snitch 15) Talebearer 16) Taleteller 17) Tattler 18) Telltale 19) Too-willing witness 
A tattletale is someone who tattles (reports others` wrongdoings), often by a child seeking attention. Tattletale or variant, may also refer to: ...
[n] - someone who gossips indiscreetly
tattler noun someone who gossips indiscreetly