/krip'teuh zoh"ik/ , adj.
1. ( cap. ) Geol. of or pertaining to that part of Precambrian time whose stratigraphic record yields only sparse, primitive fossils.
2. Zool. living in concealed or secluded places.
n.
3. ( cap. ) Geol. the part of Precambrian time whose stratigraphic record yields only sparse, primitive fossils.
[ 1890-95; CRYPTO- + ZO- + -IC ]