Source : Webster's Revised Unabridged Dictionary (1913)

Odal \O"dal\, n. [Cf. Icel. [=e]?al, Dan. odel allodial, Sw.
   odal.] (Law)
   Among the early and medieval Teutonic peoples, esp.
   Scandinavians, the heritable land held by the various odalmen
   constituting a family or kindred of freeborn tribesmen; also,
   the ownership of such land. The odal was subject only to
   certain rights of the family or kindred in restricting the
   freedom of transfer or sale and giving certain rights of
   redemption in case of change of ownership by inheritance,
   etc., and perhaps to other rights of the kindred or the
   tribe. Survivals of the early odal estates and tenure exist
   in Orkney and Shetland, where it is usually called by the
   variant form {udal}.

Odal \O"dal\, a. (Law)
   Noting, or pert. to, odal land or ownership.