What word contains three sets of double letters in a row?

Woolloomooloo

Woolloomooloo is a harbourside, inner-city eastern suburb of Sydney, in the state of New South Wales, Australia. Woolloomooloo is located 1.5 kilometres east of the Sydney central business district, in the local government area of the City of Sydney.

The suburb is located in a low-lying, former docklands area at the head of Woolloomooloo Bay, on Sydney Harbour. The Domain sits to the west, the locality of East Sydney is near the south-west corner of the suburb and the locality of Kings Cross is near the south-east corner.

The suburb has historically been a poorer working class district of Sydney. This has changed only recently with recent gentrification of the inner city areas of Sydney. The redevelopment of the waterfront, particularly the construction of the housing development on the Finger Wharf, has caused major change. Areas of public housing (housing commission) still exist in the suburb.

https://en.wikipedia.org/wiki/Woolloomooloo,_New_South_Wales

[Swapped out broken reference link. - McG]

Bookkeeper and bookkeeping.

"Bookkeeper" and "bookkeeping" and "sweet-toothed" have three consecutive sets of double letters.

Others are "deer-reeve," "feed-door," "heel-loop," "hoof-footed," "hoot-toot," "keek-keek," "Soonnee," "toot-toot," "veneer-room," and "wood-deer."

"Subbookkeeper" is the only word found in an English language dictionary with four pairs of double letters in a row.

https://www.theguardian.com/notesandqueries/query/0,5753,-9347,00.html