(a.) Not bent or arched; not bowed down.

arrowlike dead straight direct even flat horizontal in a line level lineal linear rectilineal rectilinear right ruler-straight smooth straight straight-cut straight-front straight-side streamlined TRUE unbeaten unbending unbent unbroken unconquered uncurved undefeated undeflected undeviating undistorted uninterrupted unquelled unsubdued unswerving unturned unvanquished upright vertical