doubles in length

[jaysplace2]

There is only one word in the english language that doubles in length when it is in the plural. What is it?

[Big Al1st]

Hi Jay, Dunno if it is the only one
Ox = Oxen

[Solarjunkie]

I > we?

[jaysplace2]

thank you big AL1st think that may be it

[Grunty]

If we include American English, axe is spelt ax. The plural is axes.

[Xollob]

Balderdash.
"You've had two goes, it's my go now."
"The noes won by a narrow majority."
"Two of my exes live in Smegglewick; another ex lives in Thrumpton."
"Mind your Ps and Qs."
"On the Buses" was the official title of this rather sad 60s British comedy, but "busses" (six letters) is a valid alternative plural form of the three-lettered "bus".
"Hoes" is also one of the plural forms of the somewhat colloquial "ho".
Etc. etc...

[Quizmonkey]

Oxen is probably the answer they want - but there are others. No is pluralised as noes (as in 'the noes have it').

[Quizmonkey]

Excellent answer Xollob - we must have been typing at the same time.