in law, an obligation undertaken by one party that another shall pay or perform that for which he is or may become liable to a third party. In mercantile transactions in Scotland it may be constituted in any way by which the consent of the guarantee obligant is truly and freely given; but it can only be proved by his oath or writing. The evidence of witnesses is inadmissible, unless the obligation was undertaken as an integral part of a transaction relative to moveables, provable by witnesses, or that something followed on the faith of it, with the knowledge of the guarantee obligant, by which the rights of parties were materially affected. In England it is enacted by statute, that "No action shall be brought whereby to charge the defendant upon any special promise to answer for the debt, &c., of another person, unless the agreement on which such action shall be brought, or some memorandum or note thereof, shall be in writing, and signed by the party to be charged therewith, or some other person thereunto by him lawfully authorized." The construction of all such obligations is never extended beyond their obvious meaning, and they are only understood to apply to future, unless they expressly include past transactions. All their conditions and limitations must be carefully regarded, otherwise they become void. If so expressed or intended, however, such obligations may be of the most unqualified character; they may be unlimited in amount, and indefinite as to time. When the guarantee obligant is compelled to pay, he has an action of relief against the principal debtor; but that party, being primarily liable, must first be sued by the creditor; and whatever he does towards the extinction of the claim of the creditor, or whatever the creditor recovers from him or his estate, goes so far to relieve the guarantee obligant, who can also plead against the creditor any defence which could be competently pleaded by the principal debtor. Where more persons than one are bound together in a guarantee obligation, any of them seeking relief from the others of a share of his loss must communicate to them a share of any security which he may hold over the estate of the principal debtor, or of any abatement he may have obtained from the creditor. A guarantee obligation may be extinguished by the extreme neglect of the creditor; as, for example, by his failing to take advantage of a security in his power, omitting to negotiate a bill, inadvertently giving up funds of the principal debtor over which he had a right of lien or retention, or renouncing any security over his estate. In like manner, if he compound with, or discharge the principal debtor, without the concurrence of the guarantee obligant, the guaranty is at an end; excepting under a commission of bankruptcy in England, or a sequestration in Scotland, where the creditor may, by acquiescence, allow the principal debtor to be discharged, and may accept a composition, without discharging the guarantee, provided the guarantee obligant has previously been duly warned and called on to satisfy the debt.