wtf...I'd never even have the time to look for the words I'm thinking of...I'm just gonna watch this go on and if I happen to get an idea when there have been like millions of clues I'll give it a shot (if it ever gets that far) *dumbass*
Oh crap. I dunno why but I was thinking you said 15 letters for some reason. Then how about these: - abiogenically - absorbability - catabolically - ceremoniously - equidistantly I'll stop there for now I guess.
Nope! Remember that I said the word has only been used once in the forums entire history. Previous to your post, some of those words had never been used here.
Alright, it's Saturday, so it's time for a new clue: 03. The word is a noun. Prize has diminished, as well.
Trust Mark to come up with something that will haunt me forever. Why did you specifically use the number "thirteen" to tell us about the letter?
With the clues you give us Mark, you may have well as said 'its an english word that has been used a minimal of 100 times since its invention', and it would have been easier.