Originally Posted by HareBrain
You can't say
It's 1940s British slang, apparently. Must have taken some time to cross the Atlantic. (Perhaps because the seamen were otherwise engaged.)
He was actually unaware of the term and he was just making up a name. When, later, he was clued into it's more vulgar association he wanted to go back and change the name (and I think in later publications Wankh was in fact changed to another name, can't recall what though).
edit: Here we are, from the Wiki
The editors of the Vance Integral Edition restored the author's preferred title for the first book: The Chasch. They also altered the second to The Wannek and replaced 'Wankh' with 'Wannek' throughout the text. Vance was convinced to change the name after being informed of the meaning of the word 'wank' in British and Commonwealth slang.
2nd edit: BTW, I finished A Song for Arbonne by Guy Gavriel Kay, and loved it. Gorgeous novel. And I'm starting Pushing Ice by Alastair Reynolds.