curiosity vs physical object

curiosity and physical object both are nouns.

Word	Noun	Adjective	Verb	Adverb
curiosity	Yes	No	No	No
physical object	Yes	No	No	No

As nouns, physical object is a hypernym of curiosity; that is, physical object is a word with a broader meaning than curiosity:

curiosity: something unusual -- perhaps worthy of collecting
physical object: a tangible and visible entity; an entity that can cast a shadow

Other hypernyms of curiosity include object.

curiosity (noun)	physical object (noun)
something unusual -- perhaps worthy of collecting	a tangible and visible entity; an entity that can cast a shadow
a state in which you want to learn more about something