first law of thermodynamics vs law of conservation of energy

first law of thermodynamics and law of conservation of energy both are nouns.

Word	Noun	Adjective	Verb	Adverb
first law of thermodynamics	Yes	No	No	No
law of conservation of energy	Yes	No	No	No

As nouns, first law of thermodynamics and law of conservation of energy are synonyms defined as:

first law of thermodynamics and law of conservation of energy: the fundamental principle of physics that the total energy of an isolated system is constant despite internal changes

Other synonyms of first law of thermodynamics include conservation of energy.

first law of thermodynamics (noun)	law of conservation of energy (noun)
the fundamental principle of physics that the total energy of an isolated system is constant despite internal changes	the fundamental principle of physics that the total energy of an isolated system is constant despite internal changes