modified
cheerily, gladly, willingly, readily, happily, merrily, joyfully, lightheartedly, blithely, brightly, vivaciously, airily, buoyantly, genially, jovially, sportively, elatedly, pleasantly, gleefully, gaily, mirthfully, playfully, hopefully, optimistically, breezily, briskly, with good cheer; see also happily 2.
Antonyms unwillingly, grudgingly, gloomily.