peculiarity vs physical object

peculiarity and physical object both are nouns.

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

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

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

Other hypernyms of peculiarity include object.

peculiarity (noun)	physical object (noun)
something unusual -- perhaps worthy of collecting	a tangible and visible entity; an entity that can cast a shadow
a distinguishing trait
an odd or unusual characteristic