signal-to-noise vs S/N

signal-to-noise and S/N both are nouns.

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

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

signal-to-noise and S/N: the ratio of signal intensity to noise intensity

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

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