Relatively few English words both begin and end with the letter "k".  Kiosk is one.  The word kiosk can be traced to the Persian word, kūsht, which refers to a palace or villa.  In Turkish, the word became köşk.  In France, a small structure placed in a garden became known as a kiosque.  The English form of the word, kiosk, has become generalized to denominate a variety small structures such as newsstands.  These lines from Canto III of The Corsair by Lord Byron recall the Turkish antecedents of kiosk:

The cypress saddening by the sacred Mosque,
The gleaming turret of the gay Kiosk;

The word kiosk is not presently found in the California Financial Code, but two state senators have recently introduced a bill, SB 401 (Limón & Atkins) that would regulate "digital financial asset transaction kiosks", which are defined as electronic information processing devices that accept or dispense cash in exchange for a digital financial asset.  The bill would limit transaction charges and prohibit daily transactions in excess of $1,000 with residents.  An operator would also be required to provide to the Department of Financial Protection & Innovation with a list of all locations of digital financial asset transaction kiosks that the operator owns, operates, or manages in California and would require the DFPI to make that list for each operator available to the public on its internet website.  

Other English words that start and finish with a "k" include kapok, kayak, kerplunk, kinfolk, kink, knack, knapsack, and knock. However, the k is voiced in only some of these words. The Greeks used the letter "k" (κάππα)  in many words.  Although the Roman alphabet includes "k", it is found in only a very few words, such as kalends, because the Romans had another letter - "c"- to indicate the same sound.