buoyant (adj.)youdaoicibaDictYouDict[buoyant 词源字典]
1570s, perhaps from Spanish boyante, present participle of boyar "to float," from boya "buoy," from Dutch boei (see buoy (n.)). Of personalities, etc., from c. 1748. Related: Buoyantly.[buoyant etymology, buoyant origin, 英语词源]