Webster's Revised Unabridged Dictionary · 1913

Neocomian

Neocomian , noun

[From Neocomium, the Latin name of Neuchatel, in Switzerland, where these rocks occur.]

(Geology) A term applied to the lowest deposits of the Cretaceous or chalk formation of Europe, being the lower greensand.

Neocomian , adjective

(Geology) Of or pertaining to the lower greensand.