english - Longest Word With *Only* Repeating Character Pairs

Inspired by and Opposite of: Longest Word without repeating character-pairs

The challenge is to find an English word in which every character pair appears at least twice. ("Word" does not include acronyms or proper names. Hyphenated words are included but the hyphen doesn't count as part of a pair.)

Bad word: mama contains the pair ma twice but am only once
Bad word: aa seems clever but still only has the pair once.
Good "word": aaa is not a word but it does contain its only pair aa twice.

Preference will be given to words found on Dictionary.com

Here's a check method in Excel: Input the word in the cell A1 and then input this formula somewhere else as an array formula using Ctrl+Shift+Enter: (TRUE = valid word, FALSE = invalid word)

=(SUM(LEN($A$1)-LEN(SUBSTITUTE(UPPER($A$1),MID(UPPER($A$1),ROW(OFFSET($A$1,0,0,LEN($A$1)-1)),2),"")))/4)+1>=LEN($A$1)

I've been told this javascript function will perform the same check although I haven't used the language in years and can't verify:

function test(e){for(l=[],i=1;i

NOTE: The answers thus far and the scratches I tried to come up with were all of the form [string][same string][first letter of string]. I'd be interested in finding one of a different form although the longest of any form will be accepted as the answer.

Answer

I've found a possible word, though it seems... invalid

11 letters

kinnikinnik
It's on Dictionary.com as kinnikinnick, though it includes the above form in the "Also" section.