Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
mendaciously is an adverb meaning "in a mendacious and untruthful manner". It carries one recorded sense.
in a mendacious and untruthful manner
“I told him, quite untruthfully, that I had just returned from leave”
Definitions, synonyms and semantic relations for mendaciously come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.