"courageously," 1861, from game (adj.2) + -ly (2). In Old English and Middle English the adverb meant "artfully; joyfully."
he was seen by a shepherd, gamely negotiating a particularly tricky section of the mountain road to San Doloroso
gambrel
game
game-cock
gamekeeper
gamelan
gamely
gamer
gamete
gamey
gamin
gamine