Iota - Definition and Overview

Iota (upper case Ι, lower case ι) is the 9th letter of the Greek alphabet. In the system of Greek numerals it has a value of 10.

Iota is pronounced like a 'continental' i or English ee. In ancient Greek it occurred in both long and short versions, but this distinction has been lost in Modern Greek.

Upsilon participated as the second element in falling diphthongs, with both long and short vowels as the first element. Where the first element was long, the iota was lost in pronunciation at an early date, and was written in polytonic orthography as iota subscript in other words as a very small ι under the main vowel, for instance ᾼ ᾳ ῌ ῃ ῼ ῳ

The word iota is also used in English to express a very small amount, because iota is the smallest letter in the Greek alphabet.

The Iota symbol is used to sort items in the APL programming language.

Letters that arose from Iota include the Roman I.