Cretaceous /(krē̇*tā"shŭs)/

Cre·ta·ceous

Cretaceous

a.
  1. Having the qualities of chalk; abounding with chalk; chalky; as, cretaceous rocks and formations. See Chalk.
  2. Of, pertaining to, or designating, the period of time following the Jurassic and preceding the Paleogene. See Cretaceous period below. (Geol.)

Phrases & Compounds
Cretaceous acid
an old name for carbonic acid.
Cretaceous formation
the series of strata of various kinds, including beds of chalk, green sand, etc., formed in the Cretaceous period; -- called also the chalk formation. See the Diagram under Geology.
Cretaceous period
the time in the latter part of the Mesozoic age during which the Cretaceous formation was deposited.