Like a favorite urban legend, like the discussion of cat predation, the
etymology of "jizz" keeps coming back to haunt us. And again and again
the legend is repeated that it came from the RAF during World War II,
from "general impression, size and shape." I'm convinced this is nothing
but a "folk etymology," a likely story made up by people who don't know
anything about the subject but have latched onto an idea that sounds good.

To help bury this legend once and for all, I'm reposting authoritative
information from the Oxford English Dictionary, posted on Birdchat about a
year ago, that provides the real origin of the word.

Burt Guttman guttmanb at elwha.evergreen.edu
The Evergreen State College Voice: 360-866-6000, x. 6755
Olympia, WA 98505 FAX: 360-866-6794
-----------------------

Both Lack and Campbell's _A Dictionary of Birds_ (1985) and
the OED (1989) provide a quite different source for the
origin of jizz. They refer us to a book by T. A. Coward,
published in London in 1922, titled _Bird Haunts & Nature
Memories._ This is what Coward wrote (as quoted in the OED,
p. 246; page numbers in the quotation are references to Coward):

A West Coast Irishman was familiar with the wild creatures
which dwelt on or visited his rocks and shores; at a glance he
could name them, usually correctly, but if asked how he
knew them would reply 'By their "jizz".' What is jizz?.. We
have not coined it, but how wide its use in Ireland is we
cannot say... Jizz may be applied to or possessed by any
animate and some inanimate objects, yet we cannot clearly
define it. A single character may supply it, or it may be the
combination of many (p. 141).

... Jizz, of course, is not confined to birds. The small
mammal and the plant alike have jizz (p. 143).

So, here we have it. Jizz long predates the Second World War but
was used in the early part of the century, at least on the West Coast
of Ireland, with the same meaning we now give to it in birding and
with the same meaning as that captured by the GISS acronym.