Green’s Dictionary of Slang

pure merino n.

[Merino sheep, a variety of sheep with especially fine wool, introduced from Spain to England in the late 18C and used for the improvement of the fleece-bearing sheep of Britain and the colonies. AND notes ‘one who finds in this a basis for social pretension’]

‘an early immigrant to Australia with no convict origins; a member of a leading family in Australian society; a person of fine breeding or good character’ (OED); a person with good manners; note extrapolation in cit. 1955.

[Aus]P. Cunningham New South Wales II 116: The pure merinos [...] pride themselves on being of the purest blood in the colony.
[Aus]Colonial Times (Hobart, Tas.) 18 Mar. 5/4: We have heard of a ball [...] to which a lady lately married was invited, hut whose husband was not considered sufficiently aristocratical to be admitted among the pure merinos.
[Aus]Truth (Sydney) 26 May 6/1: Another big backer [...] ‘did’ the family estate [...] but this young merino didn’t have half Wood’s brains.
[UK]E.E. Morris Austral Eng. 291/1: Merinoes, Pure, n. [...] the ‘very first families.’.
[Aus]Bulletin (Sydney) 28 Sept. 15/1: There were only two not dancing at the time – a dejected-looking coppertail, who answered to the name of Smooger, and an auburn-topped damsel, a silvertail of the choicest brand of pure merino.
[Aus]Sun. Times (Perth) 23 July 1/1: The a Bunbury dramatic club is the purest of pure merino [and] only aristocrats are eligible for admission.
[Aus]J. Doone Timely Tips For New Australians 22: TO BE ‘THE PURE MERINO.’—To show good breeding.
[Aus](con. 1830s–60s) ‘Miles Franklin’ All That Swagger 53: He was a pure merino who would not abscond from a fine young wife and children.
[Aus]Baker Popular Dict. Aus. Sl. 46: Merino, pure, originally, a free settler. Later, members of the alleged ‘leading families’.
[Aus]Cusack & James Come in Spinner (1960) 247: The real goods. You can tell the pure merinos in a minute after jumped-up bitches like D. D. T. and her crowd.
[Aus]N. Pulliam I Travelled a Lonely Land (1957) 7: [note] Dinkum Aussies — born, bred, dyed-in-the-Merino Australians.