acoel /ˈeɪsiːl/ noun2 •Any of the order Acoela of xenacoelomorphs that resemble flatworms and were originally classified as such. •A member of the order Acoela of marine flatworms, which lack a digestive cavity with definite walls.Acoels have no brain or ganglia but a network of nerves beneath the skin that is slightly more concentrated towards the front end. — 2012 formsacoels
