noun pl. i's

1. the ninth letter of the English alphabet: via Latin from the Greek iota, a modification of the Phoenician (Semitic yodh, a hand): this letter, first dotted in the 11th cent., was not distinguished from j until the 17th cent.
2. any of the speech sounds that this letter represents, as, in English, the vowel (i) of pick, (ē) of pique, or (ī) of pike, or, when it is unstressed, (ə) as in sanity, or the semivowel (y) in boil
3. a type or impression for i or I
4. the ninth in a sequence or group
5. an object shaped like

adjective

1. of i or I
2. ninth in a sequence or group
3. shaped like