whippersnapper

[ hwip-er-snap-er, wip- ]

/ ˈʰwɪp ərˌsnæp ər, ˈwɪp- /

an unimportant but offensively presumptuous person, especially a young one.

Origin of whippersnapper

1665–75; probably blend of earlier whipster and snippersnapper, similar in sense; see whip, snap, -er¹

We meet our snapper first as a whippersnapper—shot by who knows?

How Horst Captured Dietrich, Rita Hayworth, and Vivien Leigh—and Changed Fashion Photography |Patrick Strudwick |September 8, 2014 |DAILY BEAST
Here is the proof: even as a whippersnapper, young Rand seemed to love the cornea.

Found: Rand Paul's Secret Papers |Kent Sepkowitz |June 21, 2010 |DAILY BEAST
What any decent, respectable, hard-working man would do,—bring back the girl and horsewhip that whippersnapper.

Green Valley |Katharine Reynolds
By my sowl thin, you know betther thoughts than your own, Mr. Whippersnapper, if that's the name you go by.

Stories of Comedy |Various

You don't mean to say, Aaron Bickford, that you let a whippersnapper like that defy you?

The Young Acrobat of the Great North American Circus |Horatio Alger Jr.
Would you try to frighten me with that whippersnapper thing?

Little Johannes |Frederik van Eeden
And a whippersnapper fellow like Perez, a narrow-minded slow-coach, with no taste or spirit, dared to dispute the place with him!

Froth |Armando Palacio Valds

whippersnapper

/ (ˈwɪpəˌsnæpə) /

an insignificant but pretentious or cheeky person, often a young one Also called: whipster

C17: probably from whipsnapper a person who snaps whips, influenced by earlier snippersnapper, of obscure origin