From Longman Dictionary of Contemporary Englishswimminglyswim‧ming‧ly /ˈswɪmɪŋli/ adverb old-fashioned → go swimmingly
Examples from the Corpus
swimmingly• Somehow, this mix all works out swimmingly.• Everything had been going swimmingly only a moment before.• Things were going swimmingly, what with remarkably honest plumbers, electricians and carpenters fixing up my new home. 