facultative

Pronunciation key ( fak′ʼl-tā′tiv ) ( fak′əl·tā·tiv )

fac•ul•ta•tive

adj.

[Fr. facultatif <L. facultas see FACULTY]

1. relating to faculty or faculties.
2. imparting power or authority, enabling, qualifying
3. granting a faculty, or permission.
4. empowering but not requiring one to perform an action as distinguished from an obligatory requirement.
5. Permissive, therefore,
   • optional use of authority,
   • what may or may not occur; contingent.
6. relating to faculty or faculties.
7. in biology, thriving under unusual conditions, adapting to a new environment, said of parasites and aerobic bacteria, which may become anaerobic: distinguished from obligate.

References

Webster's New World Dictionary of the American Language (College Edition) ©1955

Funk and Wagnalls Standard Dictionary, Comprehensive International Edition, ©1976