also coigne, an archaic spelling of quoin (q.v.) the survival of which is due to Shakespeare's coign of vantage ("Macbeth" I.vi.), popularized by Sir Walter Scott; in this phrase it is properly "a projecting corner" (for observation).
late 14c., paiement, "action of paying, repayment of a debt; amount due as a payment," from Old French paiement (13c.), from paiier (see pay (v.)). Meaning "thing or sum of money given in discharge of a debt" is from mid-15c.
mid-15c., "one to whom any return is due or payable, one to whom money is owed," from Anglo-French creditour, Old French creditor (early 14c.), from Latin creditor "truster; lender," from creditus, past participle of credere "to believe" (see credo).