Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
swimmingly is an adverb meaning "with no problems or difficulties". It carries one recorded sense.
with no problems or difficulties
“put the plans into effect quickly and smoothly”
“despite of some mishaps, everything went swimmingly”
Definitions, synonyms and semantic relations for swimmingly come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.