Buoyant (adjective)

1. Tending to float on a liquid or rise in air or gas; characterized by liveliness and lightheartedness.
2. Able to keep afloat.

Origin:

Middle english boiant, from old french buiant, present participle of buer to float, from latin buoyare, frequentative of volare to fly.

Examples:

1. The buoyant raft easily supported their weight.
2. Despite the bad news, she remained buoyant and optimistic.
3. The stock market's buoyant performance in recent months.
4. Buoyant spirits and a positive attitude helped her through the tough times.
5. Buoyant helium balloons rose into the sky.