debutant (n.)

"first appearance in public or before society," 1751, from French début "first appearance," a figurative use from débuter "make the first stroke at billiards," also "to lead off at bowls" (a game akin to bowling), 16c., from but "mark, goal," from Old French but "end" (see butt (n.3)). The verb is first attested 1830. Related: Debuted; debuting.

Début can only be pronounced as French, and should not be used by anyone who shrinks from the necessary effort. [Fowler]