What is Cauntio Muciana?

Legal Definition
Security given by an heir or legatee, in older to obtain immediate possession of the inheritance or legacy, binding him and his surety for his observance of a condition annexed to the bequest, where the act which is the object of the condition is one which he must avoid committing during his whole life, e. g., that he will never marry, never leave the country, never engage in a particular trade, etc. See Mackeld. Rom. Law, ยง 705.
-- Black's Law Dictionary