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