Fcenns nauticum

Nautical or maritime interest. An extraordinary rate of interest agreed to be paid for the loan of money on the hazard of a voyage; sometimes calied "usura mantma." Dig. 22, 2; Code, 4, 33; 2 Bl. Comm. 458. The extraordinary rate of interest, proportioned to the risk, demanded by a person lending money on a ship, or on "bottomry," as it is termed. The agreement for such a rate of interest is also called "fœnu nauticum."' (2 Bl. Comm. 458 ; 2 Steph. Comm. 93 ) Mozley & Whitley.
—Fœnus unciarium. Interest of one-twelfth, that is, interest amounting annually to one-twelfth of the principal, hence at the rate of eight and one-third per cent, per annum. This was the highest legal rate of interest in the early times of the Roman republic. See Mackeld. Rom. Law, § 382.

Defined under Fœnus in Black's Law Dictionary.