physics vs natural philosophy

physics and natural philosophy both are nouns.

Word	Noun	Adjective	Verb	Adverb
physics	Yes	No	No	No
natural philosophy	Yes	No	No	No

As nouns, physics and natural philosophy are synonyms defined as:

physics and natural philosophy: the science of matter and energy and their interactions

physics (noun)	natural philosophy (noun)
the science of matter and energy and their interactions	the science of matter and energy and their interactions
the physical properties, phenomena, and laws of something