planetesimal vs celestial body

planetesimal and celestial body both are nouns.

Word	Noun	Adjective	Verb	Adverb
planetesimal	Yes	No	No	No
celestial body	Yes	No	No	No

As nouns, celestial body is a hypernym of planetesimal; that is, celestial body is a word with a broader meaning than planetesimal:

planetesimal: one of many small solid celestial bodies thought to have existed at an early stage in the development of the solar system
celestial body: natural objects visible in the sky

Other hypernyms of planetesimal include heavenly body.

planetesimal (noun)	celestial body (noun)
one of many small solid celestial bodies thought to have existed at an early stage in the development of the solar system	natural objects visible in the sky