Brewer's: Udal Tenure
The same as “allodial tenure,” the opposite of “feudal tenure.” Feudal tenure is the holding of a tenement of land under a feudal lord. Udal tenure is a sort of freehold, held by the right of long possession.
(Icelandic, othal, allodial.)
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894