A crotchet in British English is one beat - a quarter in American English.
In French, the very similar word croche means a quaver (eighth note), just half the value of a crotchet.
The two words are too similar for them not to have come from the same root word - which is French for crooked, bent, hooked; a crochet is a little hook, we use the same word for a kind of knitting. Now, a crotchet (English) looks less like a hook than a quaver, so pictorially, the French term is pretty accurate. (They call a one beat note la noire (the black), again a more descriptive term)
Question - why and how did we end up with crotchet as the English term for that note value?
Question number 20,000! Well, it would've been...