pattern, adj. — Green’s Dictionary of Slang

pattern adj.

[abbr. SE pattern fair, mispron. of patron fair, ult. patron saint’s fair]

(Irish) excellent, first-rate, brilliant.

1801		M. Edgeworth Belinda (1994) 121: ‘O, lady Anne Percival is the best wife in the world,’ ‘O, lady Anne Percival is quite a pattern woman!’.
1826		23 June letter in S. Leslie Mrs Fitzherbert (1939) 260: Lady Charlotte Osborne having gone off with Mr Sackville is the last gossip. The Duke of Leeds refused his consent so they were asked at St George’s three Sundays and married there yesterday with the ladysmaid for bridesmaid. So much for a pattern young lady!