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.
From Wikipedia, the free encyclopedia. Glaucus atlanticus (common names include the sea swallow, blue angel, blue glaucus, blue dragon, blue sea slug and blue ocean slug) is a species of small, blue sea slug, a pelagic aeolid nudibranch, a shell-less gastropod mollusk in the family Glaucidae.ith the aid of a gas-filled sac in its stomach, G. atlanticus floats at the surface. Due to the location of the gas sac, this species floats upside down. The upper surface is actually the foot (the underside in other slugs and snail), and this has either a blue or blue-white coloration.