12c., a shortening of Old English ic, the first person singular nominative pronoun, from Proto-Germanic *ek (source also of Old Frisian ik, Old Norse ek, Norwegian eg, Danish jeg, Old High German ih, German ich, Gothic ik), from PIE *eg- "I," nominative form of the first person singular pronoun (source also of Sanskrit aham, Hittite uk, Latin ego (source of French je), Greek ego, Russian ja, Lithuanian aš).
Reduced to i by mid-12c. in northern England, later everywhere; the form ich or ik, especially before vowels, lingered in northern England until c. 1400 and survived in southern dialects until 18c. It began to be capitalized mid-13c. to mark it as a distinct word and avoid misreading in handwritten manuscripts.
The reason for writing I is ... the orthographic habit in the middle ages of using a 'long i' (that is, j or I) whenever the letter was isolated or formed the last letter of a group; the numeral 'one' was written j or I (and three iij, etc.), just as much as the pronoun. [Otto Jespersen, "Growth and Structure of the English Language," p.233]
The dot on the "small" letter -i- began to appear in 11c. Latin manuscripts to distinguish the letter from the stroke of another letter (such as -m- or -n-). Originally a diacritic, it was reduced to a dot with the introduction of Roman type fonts. The letter -y- also was written with a top dot in Old English and early Middle English, during the centuries when it tended to be written with a closed loop at the top and thus was almost indistinguishable from the lower-case thorn (þ). In names of U.S. highways (by 1966) it is short for Interstate (adj.).
from Latin Iberia, the ancient name of the large southwestern peninsula of Europe, from Greek Iberes, the name of a Celtic people of ancient Spain. An identical name was given to an Asiatic people near the Caucasus in what is now Georgia. Of unknown origin in both uses, but the word as applied in Spain is believed to be related to that of the River Ebro. Related: Iberian (c. 1600 as a noun; 1610s as an adjective).
also (in early use) I.B.M., initialism (acronym) attested by 1921 from International Business Machines Co.; the company name in use from 1918.
son of Daedalus in Greek mythology, from Latinized form of Greek Ikaros, a name of unknown origin, connected to Icaria and the Icarian Sea. He flew too high on artificial wings and so plunged to his death. Used allusively in English from 1580s.
prehistoric trackway from Norfolk to Dorset, Old English Iccenhilde, Icenhylte (903), which is of unknown meaning and origin. There was a Romano-British Iceni tribe in modern Norfolk. The name was transferred 12c. to the ancient Roman road from Burton on the Water to Templeborough.
fem. proper name, Medieval Latin, from Old High German Ida, which is perhaps related to Old Norse ið "work." As the name of a mountain near Troy and one in Crete (the mystic birthplace of Zeus), it probably is a different word, of unknown or non-IE origin; related: Idaean.
1861 as a place name, originally applied by U.S. Congress to a proposed territorial division centered in what is now eastern Colorado; said at the time to mean "Gem of the Mountains" but probably rather from Kiowa-Apache (Athabaskan) idaahe "enemy," a name applied by them to the Comanches. Modern Idaho was organized 1861 as a county in Washington Territory; in 1863 became a territory in its own right and it was admitted as a state in 1890.
masc. proper name, from Latin Ignatius, collateral form of Egnatius. St. Ignatius, bishop of Antioch, was one of the apostolic fathers, martyred under Trajan; a set of epistles was attributed to him. Ignatius Loyola (1491-1556) was the founder of the Jesuits. Related: Ignatian.
1703, in reference to the language, from the name of a native Algonquian people who called themselves Inoca (1725), also written Ilinouek, Old Ottawa for "ordinary speaker." The modern form represents a 17c. French spelling, pronounced "ilinwe" at that time.
The U.S. territory was created 1809, admitted as a state 1818. Illinoia figures as one of the names proposed by committee in 1784 for states formed from the Northwest Territory. It would have run across the middle of the modern state, but the north around Chicago would be in Assenisipia and the southern end in Polypotamia under this proposal attributed to Jefferson.
Related: Illinoisan (1836), which seems to be the usual form; Illinoian is used in geology to refer to one of the Pleistocene ice ages in North America (1896) and earlier it was a newspaper name (1838) and a steamboat (1837). Illinoisian (adj.) was used in England in 1818.