Etymology of "wacko"

[Laurence Horn]

At 9:03 AM -0500 1/15/06, RonButters at AOL.COM wrote:
>  >
>Thanks for the explanation. I somehow missed the step that e.g. STINKO is
>immediately derived from STINKY, not STINK. Still, in that case, how is WACKY
>derived from WACK? What is a "wack"? Didn't that have something to
>do with women
>in the army during WWII?

I don't think "wacky" has much to do with WACs.  The OED cites a
definition in the 1935 _J of Abnormal Psychology_ of "wacky" as
'insane' and derives it from "whack", as in "out of ____", which in
turn is cited in 1885.

larry