Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
tunelessly is an adverb meaning "in a tuneless fashion". It carries one recorded sense.
in a tuneless fashion
“he whistled tunelessly”
Definitions, synonyms and semantic relations for tunelessly come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.