Definition of megalencephaly in English:
megalencephaly
(also megaloencephaly)
noun ˌmɛɡəlɛnˈsɛfəliˌmɛɡəlɛnˈsɛf(ə)liˌmɛɡəlɛnˈkɛfəli
Medicine Enlargement of all or part of the brain (and usually the head), occurring as a benign inherited trait or as a manifestation of various metabolic or developmental abnormalities.
Origin
Early 20th century. From megalo- + -encephaly; apparently coined by F. W. Andrewes.