WordWeb Online

1. Distinguished from others in excellence
   "did outstanding work in human relations"; "an outstanding war record"
    
2. Having a quality that thrusts itself into attention
   "an outstanding fact of our time is that nations poisoned by anti semitism proved less fortunate in regard to their own freedom"
   - prominent, salient, spectacular, striking
    
3. Owed as a debt
   "outstanding bills"
   - owing, undischarged
    
4. Of major significance or importance
   "Einstein was one of the outstanding figures of the 20th century"
   - great

See also: conspicuous, important, of import, outstandingly, superior, unpaid

Encyclopedia: Outstanding