Webster's English Dictionary

extra

1. ex.tra \'ek-str*\ aj [prob. short for extraordinary] 1a: more than is 
   due, usual, or necessary : ADDITIONAL {~  work} 1b: subject to an 
   additional charge  2: SUPERIOR {~ quality} 
2. extra n 1: something extra or additional : as  1a: an added charge  1b: 
   a special edition of a newspaper  1c: an additional worker; specif : one 
   hired to act in a group scen e in a motion picture or stage production 2: 
   something of superior quality or grade 
3. extra av : beyond the usual size, extent, or degree {~ long}