Air Force Language (1962); Medical Slang (1994)

[Jesse Sheidlower]

>
> >  _eggbeater_--A helicopter. (RHHDAS 1936)
>
> A rather precocious entry, since helicopters were a rarely-seen curiosity
> until the Sikorsky R-4 (first flight 13 January 1942) went into series
> production.

The 1936 entry in HDAS actually refers to an autogiro, not a helicopter;
the definition in HDAS allows for both senses for _eggbeater_ and the cites
make clear which is which.

Jesse Sheidlower
OED