A notch in the blade of a pocketknife or penknife into which the end of the thumbnail may be inserted to assist with opening it. Obsolete. rare.

The projection on the tang of a pocket knife blade, which prevents the edge of the blade from striking the spring.

Cutlery. A small metal (usually ‘German silver’) plate fixed on the handle of a penknife or pocket-knife, for ornament or to be engraved with the…