iota; Ι, ι +

1. The ninth letter and fourth vowel in the Greek alphabet (Ι, ι), represented in the English alphabet as "I, i"; as a numeral, it refers to 10.
2. A small or insignificant mark or part; the "smallest possible something".
3. A very small amount of something; such as, anyone with an iota of sense would know what to do.

1. The tendency in speakers of modern Greek to use the sound of iota in place of the sound of other vowel characters; such as, eta or upsilon.
2. Also, the practice in modern Greek of giving the pronunciation of iota (ee) to certain diphthongs and long vowels.

1. The smallest bit; iota.
2. To write down briefly or hastily for later reference: such as, to jot down an address.
3. The figurative use of the word jot dates from Jesus' famous declaration recorded in Matthew 5: 18: "Till heaven and earth pass, one jot or one tittle shall in no wise pass from the law, till all be fulfilled."

In the Greek original of that passage, the word for "jot" is iota.

4. Etymology: a borrowing of Latin jota, variant spelling of Greek iota, "the letter i, the smallest letter in the alphabet", hence the least part of anything.

The verb "to make a short note of" is said to have come into existence about 1721.