Noun: An electromagnetic ray used in the diagnosis and treatment of certain bodily conditions of disease and injury because of its penetrating character. The instrumentality by which the electromagnetic ray is employed. Verb: To employ the electromagnetic ray in treatment or examination of the body. To take an X-ray photograph. The rays were discovered by Roentgen and have been known and recognized by scientists, both in and out of the medical profession since 1895. Henslin v Wheaton, 91 Minn 219, 97 NW 882.