buoyancy
/ˈbɔɪənsɪ/noun
mass noun
1- the ability or tendency of something to float in water or other fluid浮性。
1.1
- the power of a liquid to keep something afloat浮力。
1.2
- figurative an optimistic and cheerful disposition〈喻〉轻松愉快的心情。
1.3
- figurative a high level of activity in an economy or stock market〈喻〉（经济或股市的）活跃：
there is renewed buoyancy in the demand for steel.
钢铁需求又开始回升。