"penis," 1933, slang, probably from
whangdoodle, an earlier term for "gadget, thing for which the correct name is not known." Many such words (
thingy,
dingus, etc.) have been used in slang for "penis," not because the actual name was unknown, but because it was unmentionable. Another possibility is that the slang word is a variant of
whang "large, thick slice" (1634), which earlier was used in the sense of "thong" (1536) and is itself a variant of
thwang, an alternat form of
thong (see
thong).
