Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
insignificantly is an adverb meaning "in an insignificant manner". It carries 2 recorded senses.
in an insignificant manner
“some people living insignificantly among us”
not to a significant degree or amount
“our budget will only be insignificantly affected by these new cuts”
Definitions, synonyms and semantic relations for insignificantly come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.