What is Frankalmoigne?

Legal Definition
In English law. Free alms. A spiritual tenure whereby religious corporations, aggregate or sole, held lands of the donor to them and their successors forever. They were discharged of all other except religious services, and the trinoda necessitas. It differs from tenure by divine service, in that the latter required the performance of certain divine services, whereas the former, as its name imports, is free. This tenure is expressly excepted in the 12 Car. II. c. 24, § 7, and therefore still subsists in some few instances. 2 Broom & H. Comm. 203.
-- Black's Law Dictionary
Legal Definition
Free alms. A tenure whereby an ecclesiastical corporation held land without fealty and merely by prayer service for the donor’s soul.
-- Ballentine's Law Dictionary