cosmic microwave background radiation vs CBR

cosmic microwave background radiation and CBR both are nouns.

Word	Noun	Adjective	Verb	Adverb
cosmic microwave background radiation	Yes	No	No	No
CBR	Yes	No	No	No

As nouns, cosmic microwave background radiation and CBR are synonyms defined as:

cosmic microwave background radiation and CBR: (cosmology) the cooled remnant of the hot big bang that fills the entire universe and can be observed today with an average temperature of about 2.725 kelvin

Other synonyms of cosmic microwave background radiation include CMB, CMBR, cosmic background radiation, cosmic microwave background.

cosmic microwave background radiation (noun)	CBR (noun)
(cosmology) the cooled remnant of the hot big bang that fills the entire universe and can be observed today with an average temperature of about 2.725 kelvin	(cosmology) the cooled remnant of the hot big bang that fills the entire universe and can be observed today with an average temperature of about 2.725 kelvin