Green’s Dictionary of Slang

(N.Z.) a woman’s elasticated foundation garment.

1980		L. Leland Kiwi-Yankee Dict. 36: easies: Girdle; foundation garments.
1988		McGill Dict. of Kiwi Sl. 42/1: easies women’s elasticised foundation garment, called ‘step-ins’ in Australia.
1991		N.Z. Women’s Weekly 24 June 40: Later came rubberised latex girdles, sometimes called easies or roll-ons [DNZE].
2003		McGill Reed Dict. of N.Z. Sl. [as cit. 1988].