Is it ensure, insure, or assure?
"scientific study of the nervous system," 1680s, from Modern Latin neurologia, from Modern Greek neurologia (1660s), from neuro- (see neuro-) + -logia "study" (see -logy). Related: Neurological.
neurology neu·rol·o·gy (nu-rŏl'ə-jē, nyu-)n. The branch of medical science that deals with the nervous system and disorders affecting it.
The branch of medicine devoted to the study and care of the nervous system.