buoyant
BOY-untadjMeaning cheerful and hopeful; also, able to float
Memory hook BUOY-ant: bobs up like a BUOY. A wave knocks Sven’s hat into the sea, and he just laughs and bobs along like a buoy. His spirits always float back up: he is buoyant.
Despite the rain, the campers stayed buoyant, singing all the way back to their cabins.
In context The team had lost its first three games, yet the players remained buoyant, joking at practice and sure that their luck was about to turn.
Similar cheerful, upbeat, lighthearted, optimistic
Opposite depressed, gloomy, despondent
Probably from Spanish boyante, “floating,” from boya, buoy.