According to [DIN50320], wear is the continuing loss of material from the surface of a solid body due to mechanical action, i.e. contact and relative movement of a solid, fluid or gaseous counter body.
In general usage, the term "wear" is used for the process of attrition as also for its consequences. In order to distinguish them, according to [DIN50320], there can be used for the process the term "wear process" and for the consequences the terms "wear manifestation" or "wear variable".
"Wear manifestations" and "wear variables" are "wear characteristics" which apply for describing the occurrence of the wear [DIN50320].
The material removed by the wear process is designated as fines [DIN50323-2].