The work was devoted to the definition of a mechanical injury in the forensic medical literature. The study of the forensic medical terminology is important because of the absence of a uniform understanding of such terms as «injury», «wound», «wound canal», and «wounding» by different authors. Different approaches of authors towards the definition of terms and concepts cause confusion in the scientific knowledge, thus breaking its orderliness and continuity. The authors of the present article invite specialists to discuss some definitions referring to a mechanical injury.