festiviter

From fēstīvus (“joyous, festive; pleasing”) +‎ -ter, from fēstus (“feast-like; festive”).

• (Classical Latin) IPA^(key): /feːsˈtiː.u̯i.ter/, [feːs̠ˈt̪iːu̯ɪt̪ɛr]
• (modern Italianate Ecclesiastical) IPA^(key): /fesˈti.vi.ter/, [fesˈt̪iːvit̪er]

fēstīviter (comparative fēstīvius, superlative fēstīvissimē)

1. humorously, facetiously, wittily, festively

• “festiviter”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• festiviter in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette.