standard atmosphere vs standard pressure

standard atmosphere and standard pressure both are nouns.

Word	Noun	Adjective	Verb	Adverb
standard atmosphere	Yes	No	No	No
standard pressure	Yes	No	No	No

As nouns, standard atmosphere and standard pressure are synonyms defined as:

standard atmosphere and standard pressure: a unit of pressure: the pressure that will support a column of mercury 760 mm high at sea level and 0 degrees centigrade

Other synonyms of standard atmosphere include atm, atmosphere.

standard atmosphere (noun)	standard pressure (noun)
a unit of pressure: the pressure that will support a column of mercury 760 mm high at sea level and 0 degrees centigrade	a unit of pressure: the pressure that will support a column of mercury 760 mm high at sea level and 0 degrees centigrade