Origin and history of belle

"money or other benefit given as a premium or extra pay to reward or encourage work," 1773, a phrase in "Stock Exchange Latin" [Weekley], taken as "a good thing," from Latin bonus "good" (adj.), perhaps originally "useful, efficient, working," from Proto-Italic *dw-eno- "good," probably a suffixed form of PIE root *deu- (2) "to do, perform; show favor."

The correct noun form would be bonum. Specifically as "extra dividend paid to shareholders from surplus profits" from 1808. In U.S. history the bonus army was the name given to the tens of thousands of World War I veterans and followers who marched on Washington, D.C., in 1932 demanding early redemption of their service bonus certificates (which carried a maximum value of $625).

early 14c., "showy trinket or ornament," from Old French baubel "child's toy, trinket," probably a reduplication of bel, from Latin bellus "pretty" (see belle). Or perhaps it is related to babe, baby. The meaning "a trifle, thing of little or no value" is from 1630s.