In the Greek alphabet, iota (ἰῶτα) is the ninth letter of the alphabet, generally corresponding to the English letter "i." In written Greek, iota is the smallest letter, just one small stroke of the pen. Sometimes, Greek vowels and diphthongs combine in such a way that the iota becomes even smaller, just a subscript (a small letter beneath another)! In English, an iota refers to a very small amount, as in the phrase "not one iota." And yes, the word "jot" comes from iota, as Matthew 5:18 records Jesus as saying, "Not one iota, not one stroke of a letter..." with the King James Version of the Bible rendering the Greek word iota as "jot," with the meaning that neither the smallest letter, or even the smallest portion of a single letter, will fall away from the law.