A word with an incredibly diverse variety of meanings and applications, dingbat first referred to an alcoholic drink in 1838.
It quickly developed a meaning similar to words such as “doohickey,” “gizmo” and “thingamabob,” which supply terms for items with unknown names.
Throughout the next century and a half, dingbat came to denote a vast array of other concepts, including—but not limited to—one of a broad range of typographical ornaments (à la the typeface Zapf Dingbats by Hermann Zapf), a muffin, a woman who is neither your sister nor mother, a foolish authority figure, and, in the plural, male genitalia.
While the word took on its current, most common sense of “a foolish person” as early as 1905, that definition was popularized in the U.S. by the TV show All in the Family in the 1970s.
*Featured image from the cover of The Field Guide to Typography: Typefaces in the Urban Landscape by Peter Dawson London: Thames & Hudson, 2013
Useless Etymology 