adjective. ['ˈfækəlˌteɪtɪv'] granting a privilege or permission or power to do or not do something.
- incumbent on
Rhymes with Facultative
Sentences with facultative
However, it is a facultative relationship for the plant which is better off without the parasite.
adjective. ['ˈfækəlˌteɪtɪv'] not compulsory.
- de rigueur