tertiary
1. [ adjective ] coming next after the second and just before the fourth in position
Synonyms: third 3rd
Related terms: ordinal
2. [ noun ] (geology) from 2 million to 63 million years ago
Synonyms: Tertiary_period
Related terms: period Cenozoic Oligocene Eocene Paleocene Miocene Pliocene
Similar spelling:   Tertry
  territory
  territorial