1600. J. Pory, trans. Leos Africa, Introd. 35. A report, that the streights of Magellan were unrepassable.
1611. Cotgr., Irrepassable, vnrepassable, ouer which no returne can be made.
1734. Watts, Reliq. Juv., 110. Narrow Limits indeed! and when once passd, they are unrepassable.
1794. H. Boyd, Ind. Observer, No. 49, ¶ 3. The eternal shore of the unrepassable river.