kiddie vs tiddler

kiddie and tiddler both are nouns.

Word	Noun	Adjective	Verb	Adverb
kiddie	Yes	No	No	No
tiddler	Yes	No	No	No

As nouns, tiddler is a hypernym of kiddie; that is, tiddler is a word with a broader meaning than kiddie:

Other hypernyms of kiddie include child, fry, kid, minor, nestling, nipper, shaver, small fry, tike, tyke, youngster.

kiddie (noun)	tiddler (noun)
informal term for a young child	a young person of either sex