rotundal
/rə(ʊ)ˈtʌndl/adjective
1Having the shape of a rotunda; round, circular. rare.
2 Zoology. Of or relating to a rounded group of cells (nucleus rotundus) of the thalamus which forms part of the visual pathway in many non-mammalian vertebrates; designating this nucleus.
Origin
Early 17th century; earliest use found in Abraham Darcie (fl. 1623–1635), author and translator. From classical Latin rotundus rotund + -al. Compare post-classical Latin rotundalis, designating a type of script.