1. A
small distinguishing mark on the letters "i" or "j". It was originally a larger mark, first appearing in Latin manuscripts, but was shortened when Roman-style typefaces were introduced. It is thought to be derived from Iota, the smallest letter in the Greek alphabet, which was used as a diacritic below other vowels in ancient
Greek texts; others say it is derived from yodh, the smallest letter in Hebrew and Aramic alphabets.
2. A very
small part or quantity; a particle, jot, or whit.