cockhorse vs plaything

cockhorse and plaything both are nouns.

Word	Noun	Adjective	Verb	Adverb
cockhorse	Yes	No	No	No
plaything	Yes	No	No	No

As nouns, plaything is a hypernym of cockhorse; that is, plaything is a word with a broader meaning than cockhorse:

cockhorse: anything used as a toy horse (such as a rocking horse or one knee of an adult)
plaything: an artifact designed to be played with

Other hypernyms of cockhorse include toy.

cockhorse (noun)	plaything (noun)
anything used as a toy horse (such as a rocking horse or one knee of an adult)	an artifact designed to be played with