# Next word in the series

while going through the words, I found the following words have some interesting property and hence thought of what could be the next word in the series:

A, ILL, COCOON, _____ ?

After thinking for a little (no...not exactly...after a long) while, I came to know that multiple answers are possible. What can be they and how ?

• This does not seem to have enough data points to be uniquely definable. I can think of a few possibilities on how to complete the sequence, and there's no way to tell which one of them is correct. – ffao Jul 12 '17 at 10:46
• Well, @ffao, you can write down your few possibilities and explain how they fit in the series. That could turn to be a correct answer ! Good luck :-) – Mea Culpa Nay Jul 12 '17 at 12:08
• LESSEE also fits in place of cocoon. – feelinferrety Aug 14 '17 at 14:00
• @feelinferrety... that is correct! – Mea Culpa Nay Aug 14 '17 at 14:02

Here is the recipe for the next word:

A word length of which is 10 and uses only 4 letters (in mixed order), where one of the letters is used once, next is used twice, another is used three times, and the last is used 4 times.

Explanation:

Notice that the first word "A" word is just a word with single letter.
The second word - "ILL" is a word which is consisted of two letters, and one of them ("I") is used once, another one ("L") is used twice.
The third word - "COCOON" is consisted of three letters, one of which ("N") is used once, another is used twice ("C"), and the other ("O") is used three times.
So the next word should be a word which uses 4 letters, where one of the letters is used once, next is used twice, another is used three times, and the last is used 4 times.
Here is the list of the 10 letter words, where you can search the word

UPDATE:
One of the possible words found by @HughMeyers

SLEEVELESS

Also another pack of words, thanks to @Sp3000: