"Kex" is one of the more obscure words in the Scrabble dictionary — it's an archaic, dialectal British term for the dry stalk of a hollow-stemmed plant, such as the cow parsnip.
Kexes had several practical applications, from candles to archery bows, according to the citations in an 1878 edition of "Notes and Queries," a language-oriented journal from London.
"Sixty or seventy years ago my grandfather, who was the first schoolmaster in Belper, used to make his lead pencils out of dry kex and molten lead," reads one citation.
More importantly, it's one of just 70 words in Scrabble that contains both K and X.