signal/noise vs S/N

signal/noise and S/N both are nouns.

Word	Noun	Adjective	Verb	Adverb
signal/noise	Yes	No	No	No
S/N	Yes	No	No	No

As nouns, signal/noise and S/N are synonyms defined as:

Other synonyms of signal/noise include signal/noise ratio, signal-to-noise, signal-to-noise ratio.

signal/noise (noun)	S/N (noun)
the ratio of signal intensity to noise intensity	the ratio of signal intensity to noise intensity