binary compound vs H2O

binary compound and H2O both are nouns.

Word	Noun	Adjective	Verb	Adverb
binary compound	Yes	No	No	No
H2O	Yes	No	No	No

As nouns, H2O is a hyponym of binary compound; that is, H2O is a word with a more specific, narrower meaning than binary compound:

binary compound: chemical compound composed of only two elements
H2O: binary compound that occurs at room temperature as a clear colorless odorless tasteless liquid; freezes into ice below 0 degrees centigrade and boils above 100 degrees centigrade; widely used as a solvent

Other hyponyms of binary compound include common salt, sodium chloride, ammonia, calcium carbide, water, hydride.

binary compound (noun)	H2O (noun)
chemical compound composed of only two elements	binary compound that occurs at room temperature as a clear colorless odorless tasteless liquid; freezes into ice below 0 degrees centigrade and boils above 100 degrees centigrade; widely used as a solvent