That depends on your definition of a word, the longest word in a major dictionary has 45 letters ( Pneumonoultramicroscopicsilico-volcanoconiosis ), but there are longer words if you allow the use of chemical names (the chemical name for titin has 189,819 characters).
100
The alphabet.
Simply a word is a combination of 2 or more then 2 letters. So, in average the number of words is 30 to 35 that will contain 100 letters.
100
The word "hundred" represents the number 100, but if you're referring to a specific word in the alphabet where each letter corresponds to a position (A=1, B=2, etc.), then the word "litter" itself does not equal 100. To find a word that sums to 100 using this method, you would need to calculate the values of the letters in candidate words and see if they total 100.
Yes, what is a word with four letters in it. Yes, "what" is a word with four letters in it.
The letters spell the word gravid. The word uses all six letters.
The letters spell the word presidents. The word uses all ten letters.
There are total of 4 letters in this word.
The letters spell the word python. The word uses all six letters.
The letters spell the word rabbit. The word uses all 6 letters taribb.
There are 10 letters in the word "California."