The Collaborative International Dictionary of English v.0.48:

Due \Due\, adv.
   Directly; exactly; as, a due east course.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Due \Due\, n.
   1. That which is owed; debt; that which one contracts to pay,
      or do, to or for another; that which belongs or may be
      claimed as a right; whatever custom, law, or morality
      requires to be done; a fee; a toll.
      [1913 Webster]

            He will give the devil his due.       --Shak.
      [1913 Webster]

            Yearly little dues of wheat, and wine, and oil.
                                                  --Tennyson.
      [1913 Webster]

   2. Right; just title or claim.
      [1913 Webster]

            The key of this infernal pit by due . . . I keep.
                                                  --Milton.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Due \Due\, a. [OF. deu, F. d[^u], p. p. of devoir to owe, fr. L.
   debere. See Debt, Habit, and cf. Duty.]
   1. Owed, as a debt; that ought to be paid or done to or for
      another; payable; owing and demandable.
      [1913 Webster]

   2. Justly claimed as a right or property; proper; suitable;
      becoming; appropriate; fit.
      [1913 Webster]

            Her obedience, which is due to me.    --Shak.
      [1913 Webster]

            With dirges due, in sad array,
            Slow through the churchway path we saw him borne.
                                                  --Gray.
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   3. Such as (a thing) ought to be; fulfilling obligation;
      proper; lawful; regular; appointed; sufficient; exact; as,
      due process of law; due service; in due time.
      [1913 Webster]

   4. Appointed or required to arrive at a given time; as, the
      steamer was due yesterday.
      [1913 Webster]

   5. Owing; ascribable, as to a cause.
      [1913 Webster]

            This effect is due to the attraction of the sun.
                                                  --J. D.
                                                  Forbes.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Due \Due\, v. t.
   To endue. [Obs.] --Shak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

due
    adv 1: directly or exactly; straight; "went due North"
    adj 1: owed and payable immediately or on demand; "payment is
           due" [ant: undue]
    2: scheduled to arrive; "the train is due in 15 minutes"
    3: suitable to or expected in the circumstances; "all due
       respect"; "due cause to honor them"; "a long due promotion";
       "in due course"; "due esteem"; "exercising due care" [ant:
       undue]
    4: capable of being assigned or credited to; "punctuation errors
       ascribable to careless proofreading"; "the cancellation of
       the concert was due to the rain"; "the oversight was not
       imputable to him" [syn: ascribable, due, imputable,
       referable]
    n 1: that which is deserved or owed; "give the devil his due"
    2: a payment that is due (e.g., as the price of membership);
       "the society dropped him for non-payment of dues"

Moby Thesaurus II by Grady Ward, 1.0:

209 Moby Thesaurus words for "due":
   according to Hoyle, accountable, accounts payable,
   accounts receivable, acknowledgment, adequate, alleged, amount due,
   ample, anticipated, appropriate, appurtenance, arrearage, arrears,
   ascribable, assignable, attributable, attributed, authority,
   awaited, back, bad debts, balanced, barely sufficient, bill, bills,
   birthright, borrowing, charged, charges, chits, claim, cognizance,
   comeuppance, coming, coming to, commensurate, compensation,
   competent, condign, conjugal right, correct, corresponding, credit,
   credited, crediting, dead, dead ahead, debt, decent, decorous,
   defensible, demand, derivable from, derivational, derivative,
   deserts, deserved, deserving, direct, directly, divine right,
   droit, due north, dueness, dues, earned, enough, entitled to,
   entitlement, equal to, equitable, even, evenhanded, expected,
   explicable, faculty, fair, fair and square, financial commitment,
   fit, fitting, floating debt, foreseen, forthright, funded debt,
   good, good enough, guerdon, hoped-for, imminent, imputable,
   imputed, in a beeline, in arrear, in arrears, in line with,
   in prospect, in view, inalienable right, indebtedness, indebtment,
   interest, just, justifiable, justified, kosher, lawful, legal,
   level, liability, long-expected, lust, mature, maturity, meet,
   meet and right, merit, merited, meriting, meritorious, minimal,
   minimum, national debt, natural right, need, nice, normal,
   normative, obligation, on the horizon, outstanding,
   outstanding debt, overdue, owed, owing, payable, payment, pledge,
   plenty, plenty good enough, power, prerogative, prescription,
   presumed, presumptive right, pretense, pretension, probable,
   promised, proper, proper claim, property right, proportionate,
   prospective, public debt, putative, receivable, recognition,
   recompense, recompensing, redeemable, referable, referred to,
   repayment, reprisal, requisite, retaliation, retribution, revenge,
   reward, right, right and proper, righteous, rightful, rights,
   satisfaction, satisfactory, score, seemly, square, straight,
   straight across, straight ahead, straightforward, straightforwards,
   straightly, substantial, sufficient, sufficient for, sufficing,
   suitable, title, traceable, uncollectibles, undeviatingly,
   unfulfilled pledge, unpaid, unsettled, unswervingly, unveeringly,
   up to, vengeance, vested interest, vested right, warrantable,
   warranted, what is owing, worthy of



Bouvier's Law Dictionary, Revised 6th Ed (1856):

DUE. What ought to be paid; what may be demanded. It differs from owing in
this, that, sometimes, what is owing is not due; a note, payable thirty days
after date, is owing immediately after it is delivered to the payee, but it
is not due until the thirty days have elapsed.
     2. Bills of exchange, and promissory notes, are not, due until the end
of the three days of grace, (q.v.) unless the last of these days happen to
fall on a Sunday, or other holy day, when it becomes due on the Saturday
before, and not on the Monday following. Story, P. N. Sec. 440; 1 Bell's
Com. 410 Story on Bills, Sec. 283; 2 Hill, N. Y. R. 587; 2 Applet. R. 264.
     3. Due also signifies just or proper; as, a due presentment, and demand
of payraent, must be made. See 4 Rawle, 307; 3 Leigh, 389; 3 Cranch, 300.