from The Century Dictionary.
- Surrounding the mouth; situated about the mouth.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- adjective around or encircling the mouth.
Sorry, no etymologies found.
He derived the central nervous system of the Chordata from the circumoral ring of the common ancestor by means of the hypothesis that both the pre-blastoporal and the post-blastoporal parts of it disappeared. [