The Collaborative International Dictionary of English v.0.48:

Maturity \Ma*tu"ri*ty\, n. [L. maturitas: cf. F. maturit['e].]
   [1913 Webster]
   1. The state or quality of being mature; ripeness; full
      development; as, the maturity of corn or of grass;
      maturity of judgment; the maturity of a plan.
      [1913 Webster]

   2. Arrival of the time fixed for payment; a becoming due;
      termination of the period a note, etc., has to run.
      [1913 Webster]

WordNet (r) 3.0 (2006):

maturity
    n 1: the period of time in your life after your physical growth
         has stopped and you are fully developed [syn: adulthood,
         maturity]
    2: state of being mature; full development [syn: maturity,
       matureness] [ant: immatureness, immaturity]
    3: the date on which an obligation must be repaid [syn:
       maturity, maturity date, due date]

Moby Thesaurus II by Grady Ward, 1.0:

93 Moby Thesaurus words for "maturity":
   ability, accounts payable, accounts receivable, adulthood,
   adultness, age of consent, amount due, applicability, bad debts,
   bill, bills, borrowing, capability, charges, chits, close,
   competence, competency, completing, completion, conclusion,
   condition, consummation, culmination, debt, driving age, due, dues,
   end, ending, financial commitment, finish, finishing, fitness,
   fittedness, floating debt, flower of age, full age, full bloom,
   full development, full growth, fullgrownness, fullness,
   funded debt, grown-upness, indebtedness, indebtment, legal age,
   legalis homo, liability, majority, manhood, manlihood, mastery,
   maturation, mature age, mellowness, national debt, obligation,
   operability, outstanding debt, perfection, pledge, preparedness,
   prime, prime of life, proficiency, public debt, qualification,
   readiness, ripe age, ripeness, riper years, rounding off,
   rounding out, score, seasoning, suitability, suitableness,
   suitedness, tempering, termination, terminus, toga virilis,
   topping off, trim, uncollectibles, unfulfilled pledge, virility,
   windup, womanhood, womanlihood, years of discretion



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

MATURITY. The time when a bill or note becomes due. In order to bind the
endorsers such note or bill must be protested, when not paid, on the last
day of grace. See Days of grace.