Русско-англо-русский юридический словарь

Roman law, the law of ancient Rome from the time of the founding of the city in 753 bce until the fall of the Western Empire in the 5th century ce. It remained in use in the Eastern, or Byzantine, Empire until 1453. As a legal system, Roman law has affected the development of law in most of Western civilization as well as in parts of the East. It forms the basis for the law codes of most countries of continental Europe and derivative systems elsewhere. (Encyclopædia Britannica)

The presumption of good faith or bona fides is essentially a civil law concept with a long history going back to Roman law that is specifically made applicable in contract law. The term is applied to all kinds of transactions. Thus, Art. 527 of the Civil Code states: Good faith is always presumed, and upon him who alleges bad faith on the part of a possessor rests the burden of proof. (http://manilastandardtoday.com)

In civil-law countries (e.g., Germany, Japan) legacy and legatee have somewhat different meanings than in Anglo-American law. In Roman law, upon the death of a person, the totality of his legal rights and duties passed to a universal successor, the heir. If there was no valid testament, the heir was determined by the rules of intestate succession. An heir, however, could also be instituted by testament, and in his testament the testator could charge his heir with legacies—that is, duties to a third party, called a legatee, to whom the heir had to pay certain sums of money or give certain assets of the estate. (Britannica)

In Roman & Civil law, innominate contract refers to a contract which is not classifiable under any particular name. In an innominate contract, the law supplies nothing in addition to the express agreement of the parties. This type of contract was developed late in classical Roman law. The agreements did not become operational without at least part performance, even if the agreements were reciprocal. (USLegal)