Definition of faciation in US English:
faciation
noun
Ecology
A division of a climax association containing more than one of the dominant species of the association.
Origin
1920s; earliest use found in Frederic Edward Clements (1874–1945). From classical Latin faciēs face + -ation.
Pronunciation
faciation
/ˌfeɪsɪˈeɪʃən/