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Webster 1913 Edition

Adj.

[F.

sénonien

, from the district of

Sénonais

, in France.]

(Geol.)

In european geology, a name given to the middle division of the Upper Cretaceous formation.

Senonian ‎(uncountable)

(geology) The final part of the Cretaceous epoch, comprising the Coniacian, Santonian, Campanian and possibly the Maastrichtian ages