A word

Xanthippe
xanthophyll
x-coordinate
x-irradiation

There are more than 1800 of them. Would you care to be more specific?

twitter
typewritten
landfill
legally
daddy
overcook
backstabbing
babbling
mammogram
esteemed
exceed
goggle

It needs a letter 'X', too, as I understand it.

He gave an example of "bubble," where I believe "X" represents any letter which begins a word and later appears as a double in that same word.

Omigod - Now I see how to read it! Obeisance to all and sundry. I guess I took the easy way out: there's only half a page of X's in my dictionary.

Well, you know if there's a hard way, that's where I'll be.

I wrote a little program to cough them up, and I really bolloxed it.
There are probably over two thousand, as I skipped the ones where the first repitition was a single letter.
I got about 1850. I had no idea there'd be so many.

Cheers. - A.

A program?! Spill the beans, please!

I used to fool around with the old Commodore 64. I got to be pretty good with Basic.
My son gave me a copy of the Scrabble word list. It comes in handy.

My goodness! You're a forefather!