The Collins English Dictionary and Dictionary.com provide lists of the English words and phrases starting with the letter "I." The American English Collins Dictionary provides a list of words starting with "I" in American English.
The Collins English Dictionary displays up to the following information about each word: pronunciation, definition, synonyms, derived form, example sentences including the word and translation to other languages, such Spanish, Arabic and Chinese. Regarding phrases, the Collins English Dictionary displays both the definition of the phrase and a link to the dictionary entry on the main word of the phrase. For example, the dictionary entry for the phrase "I beg your pardon" provides a link to the entry on the word "pardon."
The American English Dictionary displays the definition and some example sentences for words and phrases in American English.
Dictionary.com provides the definition, origin and example sentences for both American and British English words and phrases. It also features the pronunciation of words according to the international phonetic alphabet, the syllables of each word and a recorded sample of the pronunciation of the word.
This website both creates original lexicopgraphic content and gathers information form various sources, such as the Random House Unabridged Dictionary, the American Heritage dictionaries and the Harper Collins dictionaries.