- conferring a faculty, privilege, permission, or the power of doing or not doing something: a facultative enactment.
- left to one’s option or choice; optional: The last questions in the examination were facultative.
- that may or may not take place; that may or may not assume a specified character.
- Biology. having the capacity to live under more than one specific set of environmental conditions, as a plant that can lead either a parasitic or a nonparasitic life or a bacterium that can live with or without air (opposed to obligate).
- of or relating to the faculties.
- empowering but not compelling the doing of an act
- philosophy that may or may not occur
- insurance denoting a form of reinsurance in which the reinsurer has no obligation to accept a particular risk nor the insurer to reinsure, terms and conditions being negotiated for each reinsurance
- biology able to exist under more than one set of environmental conditionsa facultative parasite can exist as a parasite or a saprotroph Compare obligate (def. 4)
- of or relating to a faculty
- Capable of functioning under varying environmental conditions. Used of certain organisms, such as bacteria that can live with or without oxygen.
- Capable of occurring along various pathways or under various conditions.
- Capable of existing under varying environmental conditions or by assuming various behaviors. Bacteria that are facultative aerobes can live in both aerobic and anaerobic environments. A facultative parasite can live independently of its usual host. Compare obligate.