Adult
Biologically, an adult is a human or other organism that has reached sexual maturity. In human context, the term adult additionally has meanings associated with social and legal concepts. In contrast to a "minor", a legal adult is a person who has attained the age of majority and is therefore regarded as independent, self-sufficient, and responsible. The typical age of attaining adulthood is 18, although definition may vary by legal rights and country.
Neurology
Neurology (from Greek: νεῦρον (neûron), "string, nerve" and the suffix -logia, "study of") is a branch of medicine dealing with disorders of the nervous system. Neurology deals with the diagnosis and treatment of all categories of conditions and disease involving the central and peripheral nervous systems (and their subdivisions, the autonomic and somatic nervous systems), including their coverings, blood vessels, and all effector tissue, such as muscle. Neurological practice relies heavily on the field of neuroscience, which is the scientific study of the nervous system.