say it: NAHN-shuh-lahnt-lee
nonchalantly is an adverb meaning "in a composed and unconcerned manner". It carries 2 recorded senses.
in a composed and unconcerned manner
“without more ado Barker borrowed a knife from his brigade Major and honed it on a carborundum stone as coolly as a butcher”
Definitions, synonyms and semantic relations for nonchalantly come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.