a.

1. 有浮力的；能浮起的
   Wood is buoyant on water.

   木頭能浮於水面。

2. 趨於上升的；上漲的
   a buoyant stock market

   行情看漲的股票市場

3. 心情愉快的；活潑的
   Children are usually more buoyant than adults.

   孩子往往比成年人快樂。

adj.

1. able or tending to keep afloat.
2. cheerful and optimistic.
3. (of an economy or market) engaged in much activity.