nonnavigable,adj.1. (Of a body of water) unaffected by the tide. [Cases: Navigable Waters 1. C.J.S. Navigable Waters § 1.] 2. (Of a body of water) incapable of allowing vessels to pass for travel or commerce. 3. (Of any vessel) incapable of being steered. Cf. NAVIGABLE.

[Blacks Law 8th]