RhymeZone: redback definitions

Definitions of redback:

noun: (Australia) A venomous spider, Latrodectus hasselti, endemic to Australia.
noun: (US) A brown and white sandpiper, Calidris alpina, native to the Northern Hemisphere; the dunlin.
noun: (slang) the yuan (CNY), the currency of the People's Republic of China (Red Chinese money)

(Definitions from Wiktionary)