Green’s Dictionary of Slang

Cuba Street Yank n.

[Cuba Street, a central street in Wellington, N.Z., where American GIs would spend time during WWII + Yank n. (2)]

(N.Z.) a brash American.

[NZ]McGill Reed Dict. of N.Z. Sl. 56: Cuba Street Yank Flashy dresser and probably loud with it, the way WWII American servicemen were perceived walking up this central Wellington street.