The Collaborative International Dictionary of English v.0.48:

Congeable \Con"ge*a*ble\, a. (O. Eng. Law)
   Permissible; done lawfully; as, entry congeable.
   [1913 Webster]

Bouvier's Law Dictionary, Revised 6th Ed (1856):

CONGEABLE, Eng. law. This word is nearly obsolete. It is derived from the
French conge', permission, leave; it signifies that a thing is lawful or
lawfully done, or done with permission; as entry congeable, and the like.
Litt. s. 279.