Q From Jim Swanson: My colleagues and I have wondered about the origin of the word crackpot. I have checked three dictionaries and they offer no clue about the etymology.
A Few of mine say anything about it either. I would guess that the assumption is that it’s a moderately obvious compound. It suggests that a person’s brain is like a cracked pot, in other words that he or she is in some way deranged. Pot was once a slang term for the skull, and something cracked was obviously defective — a older expression with a similar meaning that used the same word was crack-brain, and of course we still have the slang term cracked for someone who’s thought to be crazy (a crackhead is something different, of course).
Crackpot has been with us since the 1880s, though its first sense was that of a stupid person. The London humorous writer F Anstey (a pseudonym for Thomas Anstey Guthrie) recorded it in this sense in 1891 in a piece about short farces of the period that were performed in the more minor London music halls (I hope his attempt at recording the London dialect of the period is understandable): “Colonel Jinks’s ill-used son discovered the will, whereupon his ecstasy was quite lyrical. ‘What!’ he cried. ‘All that mine? Five thousand jimmy-oh goblets, five thousand good old golden sorcepin lids! [i.e. gold sovereigns] To think I’ve bin sech a bloomin’ crackpot all this time and never tumbled on it! I’ll be a gentleman now, and live in stoyle.’”
Within a few years, the term had moved to its modern sense of a person given to eccentric, senseless or lunatic notions.