Jot

A jot means the least or very little amount of anything, as in expressions like ‘not worth a jot’, which means that something or other is virtually worthless. It dates, according to the OED, from 1499, and is an anglicisation of the Greek iota, which when written as ‘i’, is the smallest letter of the Greek alphabet, hence generally the smallest of anything. Jot, as a verb, meaning to write a brief note, dates from the early 18th century. See also iota.