Green’s Dictionary of Slang

upper ten adj.

[upper ten n.]

socially elite, of or pertaining to the social elite.

Quincy (IL) Whig 7 May 1/3: The beauty of the whole thing was, that subsequently, the ‘upper ten’ negro, indignantly refused to sit at the same table and eat with the stewards and other colored servants [DA].
[UK]W.A. Butler Nothing To Wear 24: Researches in some of the ‘Upper Ten’ districts / Reveal the most painful and startling statistics.
[US]J.R. Lowell Biglow Papers 2nd Ser. (1880) 68: Suitin’ the Nineteenth Century an’ Upper Ten idees.
[UK] ‘’Arry on ’Igh Life’ in Punch 20 July 24: Them Hupper ten Toffs [...] do appear to be flarin’ it fine.
[Aus]Bulletin (Sydney) 30 Aug. 22/1: I’ll want you to take the arrangement of the affair, Knatchbull – you ought to be used to that sort of thing – an ‘upper-ten’ make like you.
[WI]C. Thompson These My People 44: These ‘upper-ten’ people who were so desperately trying to be gentle folk; who looked like well bred people but were not.

In compounds

upper ten push (n.) [push n. (2c)]

(Aus. prison) upper-class prisoners.

[UK]M. Davitt Leaves from a Prison Diary in Farmer & Henley Sl. and Its Analogues VII 263/1: Most of these pseudo-aristocratic impostors had succeeded in gaining admission to the stocking-knitting party, which, in consequence, became known among the rest of the prisoners as the ‘upper ten push.’ .
[UK]M. Davitt Leaves from a Prison Diary I 95: Most of them [i.e. con-men posing as nobility] had succeeded in obtaining admission to the stocking-knitting party, which, in consequence, became known among the rest of the prisoners as ‘the upper-ten push.’.
[Aus]Dead Bird (Sydney) 14 Dec. 1/1: Aristocracy is on the ascendant in Sydney. The push of the upper ten is getting very strong.
[Aus]Crowe Aus. Sl. Dict. 91: Upper ten Push, aristocratic prisoners.