Modns decimandi
Defined in 1 dictionary — Black's (1910)
Black's Law Dictionary
Henry Campbell Black, M.A. · 1910
In ecclesiastical law. A manner of tithing; a partial exemption from tithes, or a pecuniary composition prescribed by immemorial usage, and of reasonable amount; for it will be invalid as a rank modus if greater than the value of the tithes in the time of Richard I. Stim. Law Gloss.
Defined under Modus in Black's Law Dictionary.