Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
signal-to-noise is a noun meaning "the ratio of signal intensity to noise intensity". It carries one recorded sense.
the ratio of signal intensity to noise intensity
Definitions, synonyms and semantic relations for signal-to-noise come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.