Anagrams of: EOPRR_

• a large sandwich made of a long crusty roll split lengthwise and filled with meats and cheese (and tomato and onion and lettuce and condiments); different names are used in different sections of the United States

• of or relating to the null set (a set with no members)

• a quantity of no importance; thing (object:), singular, negative pronoun; pronoun, thing, singular; quantifier: negative existential

• a mathematical element that when added to another number yields the same number

• the point on a scale from which positive or negative numerical quantities can be measured

• the sight setting that will cause a projectile to hit the center of the target with no wind blowing

• indicating the absence of any or all units under consideration

• having no measurable or otherwise determinable value

• indicating an initial point or origin

• adjust (an instrument or device) to zero value

• adjust (as by firing under test conditions) the zero of (a gun)

• a collection of things (goods or works of art etc.) for public display

• (college slang) A president, especially of a university.

• Prefix.

• a common venereal disease caused by the treponema pallidum spirochete; symptoms change through progressive stages; can be congenital (transmitted through the placenta)

• a contagious disease characterized by purulent skin eruptions that may leave pock marks

• a pig fattened to provide meat

• fire iron consisting of a metal rod with a handle; used to stir a fire

• any of various card games in which players bet that they hold the highest-ranking hand