That's odd.
The 8-letter word that ends with double letters is "bookkeeper." In this word, the letter "e" is repeated twice at the end. The term refers to someone who maintains financial records or accounts for a business or organization. The repetition of the letter "e" in this word is what makes it unique in having double letters at the end.
Some six letter words that end in double letters:accessacrossapogeebamboobefallboo booboohoobungeebypasscaresscoffeecouleecuckoodecreedegreeduressegressembossenrollentreeexcessgoateeharassHawaiilayofflycheemorassmuumuupayoffpeeweepizazzrebuffrecallrecessrefillremissripoffrunoffscrollscruffsetteeshrillsoireesquallstressstrolltarifftattoothrilltoffeetoupeeunlessvoodoo
Coffee is a word. It contains double e and double f. Address contains two double letters.
Pass, moss, toss, loss, mess, thee.
That's odd.
Some six letter words that end in double letters:accessacrossapogeebamboobefallboo booboohoobungeebypasscaresscoffeecouleecuckoodecreedegreeduressegressembossenrollentreeexcessgoateeharassHawaiilayofflycheemorassmuumuupayoffpeeweepizazzrebuffrecallrecessrefillremissripoffrunoffscrollscruffsetteeshrillsoireesquallstressstrolltarifftattoothrilltoffeetoupeeunlessvoodoo
Coffee is a word. It contains double e and double f. Address contains two double letters.
Pass, moss, toss, loss, mess, thee.
The letters spell the word double.
Raccoon is a word. It includes double letters in a row.
3. Actually, it is the only English word with 3 sets of double letters in a row.
The English word BOOKKEEPING or BOOKKEEPER has three sets of consecutive double letters. SUBBOOKKEEPER is the only word with four sets of consecutive double letters, although these words should be hyphenated.
bookkeeper
double
buffcuffmuffpuffballbellbillbullcallcellmallmillmullnullpillpullrollsillselltilltelltallwallwellwillbassbosscussfusshisskisslessmessmissmassmosslosspasssasstossmuttmittbuttdollfallfellfillfull
balloon