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