The spelling of the word "cryonicses" may seem unusual, but it follows the rules of English pluralization. The root word is "cryonics" [kraɪˈɑnɪks], which refers to the practice of freezing a deceased person's body in hopes of future revival. To make it plural, the suffix "-es" is added, as in "cryonicses" [kraɪˈɑnɪksɪz]. While this may seem cumbersome, it is a common way to pluralize words ending in "-ics," such as "politics" or "physics."