Ol·i·go·cene 
(ŏlĭ-gō-sēn′, ōlĭ-)
(ŏlĭ-gō-sēn′, ōlĭ-)adj.
Of, relating to, or being the epoch of geologic time from about 34 to 23 million years ago, the third epoch of the Tertiary Period. It is characterized by further development of modern mammals, including the rise of the true carnivores and their gradual replacement of the creodonts. See Table at geologic time.
n.
The Oligocene Epoch.
- spiritous
- spiritual
- spiritual bouquet
- spiritualism
- spiritualist
- spiritualistic
- spirituality
- spiritualization
- spiritualize
- spiritualizer
- spiritually
- spiritualness
- spirituel
- spirituelle
- spirituosity
- spirituous
- spirituousness
- spiro-
- spirochetal
- spirochete
- spirochetosis
- spirograph
- spirographic
- spirographically
- spirography