(Science: zoology) A cockroach.
1. (Science: zoology) A European fresh water fish of the Carp family (Leuciscus rutilus). It is silver-white, with a greenish back. An American chub (Semotilus bullaris); the fallfish.
The redfin, or shiner.
2. A convex curve or arch cut in the edge of a sail to prevent chafing, or to secure a better fit. As sound as a roach [roach perhaps being a corruption of a F. Roche a rock], perfectly sound.
Origin: OE. Rroche; cf. AS. Reohha, D. Rog, roch, G. Roche, LG. Ruche, Dan. Rokke ray, Sw. Rocka, and E. Ray a fish.