Of, relating to, or designating a group of fossiliferous rocks of Cambrian age found near St David's in South Wales, and also near Dolgellau and Maentwrog in North Wales.
noun
The Menevian formation.
Origin
Mid 19th century. From Menevia, name in post-classical Latin of Mynyw, the former name of a town (now Tyddewi or St David's) in Pembrokeshire, Wales + -an. The forms Minevian and Maenevian may reflect variant spellings in post-classical Latin.