One of the mysteries of the English language finally explained.
Definition of Maastrichtian in US English:
Maastrichtian
(also Maestrichtian)
adjective
GeologyOf, relating to, or designating a division of the Upper Cretaceous in Europe that is now regarded as the most recent stage of the Cretaceous, lying next below the Danian of the Tertiary.
noun
GeologyThe Maastrichtian stage or age. Usually with the.
Origin
Late 19th century; earliest use found in Archibald Geikie (1835–1924), geologist and historian. From French maestrichtien from Maestricht (now Maastricht, whence the 20th-cent. respelling) + -ien.