There isn't a single, universally accepted "scientific word" for hardness. The concept of hardness is complex and has different meanings depending on the context.

Here are some terms used in different scientific fields related to hardness:

Material Science:

* Hardness: This is the most common term used to describe a material's resistance to indentation or scratching.

* Brinell hardness: A specific measurement of hardness using a steel ball indenter.

* Rockwell hardness: Another specific measurement of hardness using a diamond indenter.

* Vickers hardness: A measurement of hardness using a diamond pyramid indenter.

* Shore hardness: A measurement of hardness for rubber and plastics using a durometer.

* Knoop hardness: A measurement of hardness using a diamond pyramid indenter with a specific angle.

* Mohs hardness: A relative scale of hardness based on scratch resistance.

Geology:

* Hardness: Often used in the context of minerals and rocks.

* Mohs scale: A scale ranking minerals from 1 (softest, talc) to 10 (hardest, diamond) based on scratch resistance.

Other:

* Stiffness: Refers to a material's resistance to deformation under load.

* Strength: Refers to a material's ability to withstand stress without breaking.

* Toughness: Refers to a material's ability to absorb energy before fracturing.

The best term to use depends on the specific context and what aspect of hardness you're trying to describe.