tattler vs gossiper

tattler and gossiper both are nouns.

Word	Noun	Adjective	Verb	Adverb
tattler	Yes	No	No	No
gossiper	Yes	No	No	No

As nouns, gossiper is a hypernym of tattler; that is, gossiper is a word with a broader meaning than tattler:

tattler: someone who gossips indiscreetly
gossiper: a person given to gossiping and divulging personal information about others

Other hypernyms of tattler include gossip, gossipmonger, newsmonger, rumormonger, rumourmonger.

tattler (noun)	gossiper (noun)
any of several long-legged shorebirds having a loud whistling cry	a person given to gossiping and divulging personal information about others
someone who gossips indiscreetly