truer I. truer comparative of true II. tru·er\ˈtrüə(r); -u̇(ə)r, -u̇ə\noun (-s) Etymology:true (III) + -er : one that trues: as a.: a device for trueing abrasive wheels b.: one that trues objects (as optical lenses, green clay blocks, or springs) to bring them into correct condition, size, or alignment