Definition of "erk"

But I wasn’t accepted for flying duty—eyesight failed me. Neither was Frank, which, I’m ashamed to say, I found a relief. We were both channelled as aircrafthands, known to everyone as erks.

2004, Andrea Levy, chapter 9, in Small Island‎, London: Review, page 345

‘Gawd, erk!’ She recoiled and turned away.

1959, D'Arcy Niland, The Big Smoke, page 43

‘Erk! What’s that big ugly growth you’ve got?’

1995, Paul Vautin, Turn It Up!, page 29