in the Civil Law, an obligation, whereby the effects of a debtor are made over to his creditor, to secure his debt. The word comes from the Greek ἐπιθέσις, a thing subject to some obligation; of the verb ἐπιθέω, suppono, "I am rejected;" of ὑπό, under, and ἐπιθέω, ponō, "I put."

As the hypotheca is an engagement procured on purpose for the security of the creditor, various means have been made use of to secure to him the benefit of the convention. The use of the pawn or pledge is the most ancient, which is almost the same thing with the hypotheca; all the difference consisting in this, that the pledge is put into the creditor's hands; whereas, in a simple hypotheca, the thing remained in the possession of the debtor. It was found more easy and commodious to engage an estate by a civil covenant than by an actual delivery: accordingly the expedient was first practised among the Romans; and from them the Romans borrowed both the name and the thing: only the Greeks, the better to prevent frauds, used to fix some visible mark on the thing, that the public might know it was hypothecate or mortgaged by the proprietor; but the Romans, looking on such advertisements as injurious to the debtor, forbade the use of them.

The Roman lawyers distinguished four kinds of hypothecas: the conventional, which was with the will and consent of both parties; the legal, which was appointed by law, and for that reason called tacit; the practor's pledge, when by the flight or non-appearing of the debtor, the creditor was put in possession of his effects; and the judiciary, when the creditor was put in possession by virtue of a sentence of the court.

The conventional hypotheca is subdivided into general and special. The hypotheca is general, when all the debtor's effects, both present and future, are engaged to the creditor. It is special, when limited to one or more particular things.

For the tacit hypotheca, the civilians reckon no less than twenty-six different species thereof.