Green’s Dictionary of Slang

wop n.⁴

In phrases

up the wop [ety. unknown] (N.Z.)

1. pregnant.

1988		McGill Dict. of Kiwi Sl. 118/1: up the wop pregnant.
2003		McGill Reed Dict. of N.Z. Sl. [as cit. 1988].

2. broken, out of order.

1960		R.M. Muir Word for Word 212: The whole idea’s up the wop.
1988		McGill Dict. of Kiwi Sl. 118/1: up the wop [...] broken, not functioning.
2003		McGill Reed Dict. of N.Z. Sl. [as cit. 1988].