Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
insanely is an adverb meaning "in an insane manner". It carries 2 recorded senses.
in an insane manner
“she behaved insanely”
“he behaves crazily when he is off his medication”
“the witch cackled madly”
“screaming dementedly”
(used as intensives) extremely
“she was madly in love”
“deadly dull”
“deadly earnest”
“deucedly clever”
“insanely jealous”
intensifier
Definitions, synonyms and semantic relations for insanely come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.