(g hard). A tenure in Wales, Kent, and Northumberland, whereby land descended from the father to all his sons in equal proportions. The youngest had the homestead, and the eldest the horse and arms.
Coke (1 Institutes, 140 a) says the word is gif eal cyn (give all the kin); but Lambarde suggests the Anglo-Saxon gafol or gavel, rent; and says it means “land which yields rent”! gavel cyn, rent for the family derived from land. There is a similar Irish word, gabhailcine, a family tenure.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894