young buck

plural young bucks

1. An adventurous or high-spirited young man.

   Face it, Bernie, you're seventy-four years old ... you can't expect to be able to build a cart train as long as the young bucks.

   2005 June 17, Tom Armstrong, Marvin (comic)

   3 more examples

   Thus young Pen, the only son of an estated country gentleman, with a good allowance, and a gentlemanlike bearing and person, looked to be a lad of much more consequence than he was really; and was held by the Oxbridge authorities, tradesmen, and undergraduates, as quite a young buck and member of the aristocracy.

   1848 November – 1850 December, William Makepeace Thackeray, chapter 19, in The History of Pendennis. […], volume (please specify |volume=I or II), London: Bradbury and Evans, […], published 1849–1850, →OCLC

   Devereux, indeed, being a fast man, with such acres as he inherited, which certainly did not reach a thousand, mortgaged pretty smartly, and with as much personal debt beside, of the fashionable and refined sort, as became a young buck of bright though doubtful expectations—and if the truth must be owned, sometimes pretty nearly pushed into a corner—was beholden, not only for his fun, but occasionally for his daily bread and even his liberty, to those benovolent^([sic]) doles.

   1863, J[oseph] Sheridan Le Fanu, “In Which Captain Devereux’s Fiddle Plays a Prelude to ‘Over the Hills and Far Away’”, in The House by the Church-yard. […], volume I, London: Tinsley, Brothers, […], →OCLC, pages 307–308

   But most likely my judgement was distorted by my contempt for his acting the young buck [...] for ever waxing his moustaches and loading himself with medicaments supposed to replace the failing sap of youth, glycerophosphates, formates, nux vomica, yohimba, damiana.

   1963, Xavier Herbert, Distubing Element, Sydney: Angus and Robertson, page 178