The Collaborative International Dictionary of English v.0.48:

Remain \Re*main"\ (r?-m?n"), v. i. [imp. & p. p. Remained
   (-m?nd"); p. pr. & vb. n. Remaining.] [OF. remaindre,
   remanoir, L. remanere; pref. re- re- + manere to stay,
   remain. See Mansion, and cf. Remainder, Remnant.]
   [1913 Webster]
   1. To stay behind while others withdraw; to be left after
      others have been removed or destroyed; to be left after a
      number or quantity has been subtracted or cut off; to be
      left as not included or comprised.
      [1913 Webster]

            Gather up the fragments that remain.  --John vi. 12.
      [1913 Webster]

            Of whom the greater part remain unto this present,
            but some are fallen asleep.           --1 Cor. xv.
                                                  6.
      [1913 Webster]

            That . . . remains to be proved.      --Locke.
      [1913 Webster]

   2. To continue unchanged in place, form, or condition, or
      undiminished in quantity; to abide; to stay; to endure; to
      last.
      [1913 Webster]

            Remain a widow at thy father's house. --Gen.
                                                  xxxviii. 11.
      [1913 Webster]

            Childless thou art; childless remain. --Milton.
      [1913 Webster]

   Syn: To continue; stay; wait; tarry; rest; sojourn; dwell;
        abide; last; endure.
        [1913 Webster]

WordNet (r) 3.0 (2006):

remaining
    adj 1: not used up; "leftover meatloaf"; "she had a little money
           left over so she went to a movie"; "some odd dollars
           left"; "saved the remaining sandwiches for supper";
           "unexpended provisions" [syn: leftover, left over(p),
           left(p), odd, remaining, unexpended]

Moby Thesaurus II by Grady Ward, 1.0:

103 Moby Thesaurus words for "remaining":
   abiding, age-long, aged, ancient, antique, as a bonus, changeless,
   chronic, commorant, constant, continuing, continuous, diuturnal,
   durable, dwelling, enduring, evergreen, extant, extra, firm, fixed,
   for lagniappe, frozen, hardy, immobile, immutable, in residence,
   indefatigable, intact, intransient, inveterate, inviolate, lasting,
   left, leftover, living, living in, lodging, long-lasting,
   long-lived, long-standing, long-term, longeval, longevous,
   macrobiotic, net, odd, of long duration, of long standing,
   outstanding, over, over and above, overplus, perdurable, perduring,
   perennial, permanent, perpetual, persistent, persisting, quiescent,
   remanent, resident, residentiary, residing, residual, rigid,
   sempervirent, solid, spare, stable, static, stationary, staying,
   steadfast, steady, sticking, superfluous, supernumerary, surplus,
   surviving, sustained, to spare, torpid, tough, unaltered,
   unceasing, unchangeable, unchanged, unchanging, unchecked,
   unconsumed, undestroyed, undying, uneaten, unfading, unfailing,
   unremitting, unshifting, unused, unvaried, unvarying, vital