pluviometer vs rain gauge

pluviometer and rain gauge both are nouns.

Word	Noun	Adjective	Verb	Adverb
pluviometer	Yes	No	No	No
rain gauge	Yes	No	No	No

As nouns, pluviometer and rain gauge are synonyms defined as:

pluviometer and rain gauge: gauge consisting of an instrument to measure the quantity of precipitation

Other synonyms of pluviometer include rain gage, udometer.

pluviometer (noun)	rain gauge (noun)
gauge consisting of an instrument to measure the quantity of precipitation	gauge consisting of an instrument to measure the quantity of precipitation