Plutonium(II) Oxide Molar mass: 259.9994
<abbreviation> Pyrexia of unknown (or uncertain) origin, a term applied to febrile illness before diagnosis has been established; also referred to as FUO (fever of unknown origin). ... (05 Mar 2000) ... 
pyrexia of unknown origin.
Pyrexia of Unknown Origin - meaning a high temperature which can't be explained at the moment.
Type: Abbreviation Definitions: 1. Abbreviation for pyrexia of unknown (or uncertain) origin, a term applied to febrile illness before diagnosis has been established; also referred to as FUO (fever of unknown origin).
Pyrexia of unknown origin
Prohibited User Operation. Optional button instructions written into the authored DVD. Often used to disallow buttons from functioning. For example, during the FBI warning on commercial discs, a PUO usually prevents it being skipped by pressing menu or FF buttons.