Definition of "buoyant"

And of course, in order to understand the Earth's past and how it got to where it now is, it is important to have a basic knowledge of plate tectonics, which explains how the planet's continental and oceanic crusts are part of the lithospheric plates that are buoyant and ride upon the highly viscous asthenosphere.

2012, Chinle Miller, In Mesozoic Lands: The Mesozoic Geology of Arches and Canyonlands National Parks, Kindle edition

[...] the accelerated, high-frequency East Coast express timetable, operating this year in a buoyant economic environment, is beginning to attract more business travel to rail (although there is still a long way to go before the potential is fully realised); [...].

1964 September, G. Freeman Allen, “Interim report on the East Coast Route express service”, in Modern Railways, page 158

It[China] had a buoyant economy outperforming forecasts. Its unemployment rate was among the lowest in years. While consolidating his power for a second term, Mr Xi proudly pointed to China's "flourishing" growth model as something other countries could emulate.

2023 November 15, Tessa Wong, “Xi Jinping arrives in US as his Chinese Dream sputters”, in BBC‎