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.]
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   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.
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            Gather up the fragments that remain.  --John vi. 12.
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            Of whom the greater part remain unto this present,
            but some are fallen asleep.           --1 Cor. xv.
                                                  6.
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            That . . . remains to be proved.      --Locke.
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   2. To continue unchanged in place, form, or condition, or
      undiminished in quantity; to abide; to stay; to endure; to
      last.
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            Remain a widow at thy father's house. --Gen.
                                                  xxxviii. 11.
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            Childless thou art; childless remain. --Milton.
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   Syn: To continue; stay; wait; tarry; rest; sojourn; dwell;
        abide; last; endure.
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The Collaborative International Dictionary of English v.0.48:

Remain \Re*main"\, v. t.
   To await; to be left to. [Archaic]
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         The easier conquest now remains thee.    --Milton.
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The Collaborative International Dictionary of English v.0.48:

Remain \Re*main"\ n.
   1. State of remaining; stay. [Obs.]
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            Which often, since my here remain in England,
            I 've seen him do.                    --Shak.
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   2. That which is left; relic; remainder; -- chiefly in the
      plural. "The remains of old Rome." --Addison.
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            When this remain of horror has entirely subsided.
                                                  --Burke.
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   3. Specif., in the plural:
      (a) That which is left of a human being after the life is
          gone; relics; a dead body.
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                Old warriors whose adored remains
                In weeping vaults her hallowed earth contains!
                                                  --Pope.
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      (b) The posthumous works or productions, esp. literary
          works, of one who is dead; as, Cecil's Remains.
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WordNet (r) 3.0 (2006):

remain
    v 1: stay the same; remain in a certain state; "The dress
         remained wet after repeated attempts to dry it"; "rest
         assured"; "stay alone"; "He remained unmoved by her tears";
         "The bad weather continued for another week" [syn: stay,
         remain, rest] [ant: change]
    2: continue in a place, position, or situation; "After
       graduation, she stayed on in Cambridge as a student adviser";
       "Stay with me, please"; "despite student protests, he
       remained Dean for another year"; "She continued as deputy
       mayor for another year" [syn: stay, stay on, continue,
       remain]
    3: be left; of persons, questions, problems, results, evidence,
       etc.; "There remains the question of who pulled the trigger";
       "Carter remains the only President in recent history under
       whose Presidency the U.S. did not fight a war"
    4: stay behind; "The smell stayed in the room"; "The hostility
       remained long after they made up" [syn: persist, remain,
       stay]

Moby Thesaurus II by Grady Ward, 1.0:

118 Moby Thesaurus words for "remain":
   abide, balance, be found, be left, be located, be met with,
   be present, be situated, be still, be there, berth, bide, body,
   bunk, cadaver, carcass, carry on, cease not, coast, cohabit,
   continue, continue to be, corpse, debris, defeat time, defy time,
   detritus, domicile, domiciliate, doss down, drag on, dwell,
   dwell in, endure, exist, extend, fragments, freeze, go along,
   go on, hang out, hold, hold on, hold out, hold steady, indwell,
   inhabit, inhere, jog on, keep, keep going, keep on, keep quiet,
   last, last long, last out, leavings, leftovers, lie, lie still,
   linger, live, live on, live through, lodge, maintain, mark time,
   nest, never cease, not breathe, not stir, occupy, occur, oddments,
   odds and ends, perch, perdure, perennate, persevere, persist,
   prevail, remain motionless, remainder, remains, repose, reside,
   residue, rest, room, roost, run, run on, scraps, slog on, squat,
   stagger on, stand, stand fast, stand firm, stand still, stay,
   stay on, stay put, stick, stick around, stick fast, subsist,
   survive, sustain, tarry, tenant, tide over, traces, tread water,
   vestiges, wait, wear, wear well