#notch

• Scratch — A fine scratch, a superficial notch, or a visible mark left on a surface by a sharp object, thorn, or cutting tool. In traditional crafts, it represents the mark or guide line intentionally executed on wood or stone to outline processing references, while in daily usage it indicates a small skin lesion or an aesthetic flaw on a household object.
• Notch — A specialized technical term designating a notch, groove, or recess deliberately made on the edge of a mechanical part or a dial to allow the exact jointing, guiding, or locking of another structural element. In fine horology, the term describes the precise cutout where cases, protective crystals, or mobile escapement components are secured.
• Notch — A notch, deep indent, profiled groove, or small slot intentionally made on the surface of a mechanical part, instrument, or structural material. Its functional role is to allow guiding, locking, correct assembly with another component, or to serve as a controlled failure point in materials resistance testing.
• Antitragus — A small, cartilaginous prominence located on the pinna of the external ear (auricle), situated symmetrically at the lower part of the antihelix and placed directly opposite the tragus, from which it is separated by the intertragic notch. This fine anatomical structure plays a decorative and functional role in helping direct sound waves into the external auditory canal and also represents a common landmark in modern piercing procedures.
• Score — To score, crease, or mark a fine line, groove, or guiding notch onto the surface of a mechanical part, textile material, or sheet of paper, aiming to facilitate subsequent folding, assembly, or perfect geometric alignment. In industrial environments, the action defines the execution of a preliminary mechanical tracing operation.