principle of equivalence vs physics

principle of equivalence and physics both are nouns.

Word	Noun	Adjective	Verb	Adverb
principle of equivalence	Yes	No	No	No
physics	Yes	No	No	No

principle of equivalence (noun)	physics (noun)
(physics) the principle that an observer has no way of distinguishing whether his laboratory is in a uniform gravitational field or is in an accelerated frame of reference	the science of matter and energy and their interactions
	the physical properties, phenomena, and laws of something