Can you think of a word with four repeated letters?

For example, the word runner has two repeated letters, r and n. I posed the problem to myself of finding words with 3 repeated letters and, after a little while, was able to think of a few.

The problem of finding words with 4 repeated letters was more difficult. I did not think of any at first and stopped thinking about it. Then later on a word popped into my head and later another one. The words were relatively short, with only 2 non-repeated letters in one case and 3 in the other. I had to write them down to be certain that there were in fact 4 repeated letters.

It is interesting to think of how the mind works for such problems. There is no way to systematically attack them. Somehow use is made of the way we internally file words. There can’t be all that many words with 4 repeated letters. I would appreciate it if some of you try to find some, so I can see if the words you think of are the same as the ones I thought of.