Definition of legend for English Language Learners. : 1  a story from the past that is believed by many people but cannot be proved to be true. : 2  a famous or important person who is known for doing something extremely well. : 3  a list that explains the symbols on a map.
glaÂ·cis. n. pl. glacis. 1. a. A gentle slope; an incline. b. A slope extending down from a fortification.
Technically, each crevice is called a sulcus (pl. sulci) and each ridge between the crevices is called a gyrus (pl. gyri). Sulci and gyri are simply a way of increasing the surface area of the cerebral cortex (and therefore the number of neurons) without greatly expanding the size of the skull.nstead of being smooth and nearly featureless like a kidney or spleen, the cerebral cortex (the thin layer of gray matter forming the outer surface of the brain) is chock-full of wrinkles and folds.