Synonyms for Outstanding:

adj.

ace (adjective)
excellent.
champion (adjective)
out of sight.
different (adjective)
unusual.
exceptional (adjective)
marvelous, miraculous, exotic, unusual, peculiar, extraordinary, noteworthy, outlandish, exceptional, striking, unprecedented, excellent, phenomenal, fantastic, fabulous, notable, sensational, wonderful, remarkable, superior, Wonderous, novel.
important (adjective)
major, noteworthy.
noticeable (adjective)
arresting.
outstanding (adjective)
leading, great, owing, phenomenal, marked, prominent, magnificent, superior, distinguished, exceptional, conspicuous, pronounced, STANDOUT, unsettled, preeminent, eye-catching, remarkable, due, arresting, payable, noteworthy, major, signal, notable, salient, pending.
unpaid (adjective)
unpaid, owing.

n.

commendable, awe-inspiring, admirable, heroic, praiseworthy, enviable, respected. bold, balance, marked, liability, pointed, debit, signal, pronounced, bill, bad debt, see, arresting, borrowings, debt, observable, noticeable, home loan, eye-catching, arrears. magnificent, towering, better, pending, rare, preeminent, undone, partial, STANDOUT, sketchy, awesome, light touch, abortive, uncommon, unfinished, singular, usual, out of sight, incomplete, superficial. payable, receivable, due, unsettled, pay. outstanding (noun)
obvious, striking, owed, spectacular, conspicuous, great, major, prominent, salient, superior, undischarged, unpaid, owing.
prominent (noun)
leading, study at noticeable, distinguished.

Other synonyms:

light touch, out of sight, receivable, arresting, STANDOUT, eye-catching. partial, undone, payable, sketchy, marked, preeminent, distinguished, unfinished, towering. pending, incomplete, pronounced, uncommon. rare, superficial, observable. magnificent, singular, bold. unsettled. pointed. observable
noticeable.
outstanding
awesome.
unpaid
due, unpaid.

Usage examples for outstanding

  1. " And I'll tell you what, Mr. Vavasor,- of course I've my outstanding bills for the last affair. – Can You Forgive Her? by Anthony Trollope
  2. The married women wear also a great outstanding collar. – African Camp Fires by Stewart Edward White
  3. Toward the close of the last Administration a convention was signed at London for the settlement of all outstanding claims between Great Britain and the United States, which failed to receive the advice and consent of the Senate to its ratification. – Complete State of the Union Addresses from 1790 to the Present by Various