1. The ninth letter of the modern English alphabet.
2. Any of the speech sounds represented by the letter i.
3. The ninth in a series.
4. Something shaped like the letter I.

Usage Note: The question of when to use nominative forms of the personal pronouns (for example, I, she, they) and when to use objective forms (for example, me, her, them) has always created controversy among grammarians and uncertainty among speakers and writers. There is no problem when the pronoun stands alone with a single verb or preposition: every native speaker says I (not me) read the book; They told him (not he); The company bought a computer for us (not we); and so forth. But the decision is more problematic in other environments. · When pronouns are joined with other nouns or pronouns by and or or, there is a widespread tendency to use the objective form even when the phrase is the subject of the sentence: Tom and her are not speaking to each other. This usage is natural in colloquial speech, but the nominative forms should be used in formal speech and writing: John and she (not her) will be giving the talk. · When pronouns joined by a conjunction occur as the object of a preposition such as between, according to, or like, many people use the nominative form where the traditional grammatical rule would require the objective; they say between you and I rather than between you and me, and so forth. Many critics have seen this construction as originating in a hypercorrection, whereby speakers who have been taught to say It is I instead of It is me come further to assume that correctness also requires between you and I in place of between you and me. This explanation of the tendency cannot be the whole story, inasmuch as the phrase between you and I occurs in Shakespeare, centuries before the prescriptive rules requiring It is I and the like were formulated. But the between you and I construction is nonetheless widely regarded as a marker of grammatical ignorance and is best avoided. · In other contexts the traditional insistence that the nominative form be used is more difficult to defend. The objective form sounds most natural when the pronoun is not grammatically related to an accompanying verb or preposition. Thus, in response to the question "Who cut down the cherry tree?" we more colloquially say "Me," even though some grammarians have argued that I must be correct here by analogy to the form "I did"; and few speakers would accept that the sentence What, me worry? is improved if it is changed to What, I worry? The prescriptive insistence that the nominative be used in such a construction is grammatically questionable and is apt to lead to almost comical pedantries. · There is also a widespread tendency to use the objective form when a pronoun is used as a subject together with a noun in apposition, as in Us engineers were left without technical support. In formal speech or writing the nominative we would be preferable here. But when the pronoun itself appears in apposition to a subject noun phrase, the use of the nominative form may sound pedantic in a sentence such as The remaining members of the admissions committee, namely we, will have to meet next week. A writer who is uncomfortable about using the objective us here would be best advised to rewrite the sentence to avoid the difficulty. See Usage Notes at be, but, we.

1. The symbol for the element iodine.
2. Electricity The symbol for current.
3. also i The symbol for the Roman numeral 1.

1. incomplete
2. interstate
3. isospin

1. Symbol I² A lustrous, grayish-black, corrosive, poisonous halogen element having radioactive isotopes, especially I 131, used as a medical tracer and in thyroid disease diagnosis and therapy. Iodine compounds are used as germicides, antiseptics, and dyes. Atomic number 53; atomic weight 126.9045; melting point 113.5°C; boiling point 184.35°C; specific gravity (solid, at 20°C) 4.93; valence 1, 3, 5, 7. See Table at element.
2. An antiseptic preparation containing iodine in solution, used to treat wounds.

1. current
2. ice
3. incomplete
4. institute
5. intelligence
6. interstate
7. iodine
8. isospin
9. Italy (international vehicle ID)
10. 1