Jurassic has 4 different meanings across 3 categories:
Noun · Adjective · Proper Noun
from 190 million to 135 million years ago; dinosaurs; conifers
of or relating to or denoting the second period of the Mesozoic era
Of or pertaining to the second period of the Mesozoic era, a time still dominated by dinosaurs.
The period from 201.3±0.2 to 145 million years ago, after the Triassic and before the Cretaceous; the geologic systems of this period.