Found in the following dictionaries
TWL06 (NASPA List 2006)
"I" Definition
Word Fact:
The shortest, oldest, and most commonly used word is "I".
The shortest, oldest, and most commonly used word is "I".
noun
Any of the speech sounds represented by the letter i.
Source: American Heritage Dictionary
Something shaped like the letter I.
Source: American Heritage Dictionary
The ninth in a series.
Source: American Heritage Dictionary
The ninth letter of the modern English alphabet.
Source: American Heritage Dictionary
The 9th letter of the English alphabet.
Source: Merriam-Webster
The symbol for imaginary unit.
Source: American Heritage Dictionary
pronoun
The one who is speaking or writing.
Source: Merriam-Webster
Used by a speaker to refer to himself or herself:.
Source: Oxford Dictionary
abbreviation
Industrial.
Source: Merriam-Webster
Initial.
Source: Merriam-Webster
Intelligence.
Source: Merriam-Webster
Intensity.
Source: Merriam-Webster
Interlaced.
Source: Merriam-Webster
symbol
Imaginary unit.
Source: Merriam-Webster
Iodine.
Source: Merriam-Webster