I, ninth letter and third vowel in the English, Greek, and Roman alphabets. It was called iota by the Greeks from its Semitic name, yodh, which means “hand,” and was derived from the form of the character in the Egyptian hieratic alphabet; this bore some resemblance to a hand with the thumb held separate. The dot over the lowercase i came into general use in the 11th century. It was originally an accent, used first to indicate vowel length and later to distinguish ii from u and to mark the i in the combinations iu and ui.