Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
sneakingly is an adverb meaning "in a sneaky manner". It carries one recorded sense.
in a sneaky manner
“I always felt sneakingly that I wanted to be a concert pianist”
Definitions, synonyms and semantic relations for sneakingly come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.