facultative

[fak-uhl-tey-tiv]

adjective

1. conferring a faculty, privilege, permission, or the power of doing or not doing something.

   a facultative enactment.

2. left to one's option or choice; optional.

   The last questions in the examination were facultative.

3. that may or may not take place; that may or may not assume a specified character.

4. 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 (obligate ).

5. of or relating to the faculties.

facultative

/ ˈfækəltətɪv /

adjective

1. empowering but not compelling the doing of an act

2. philosophy that may or may not occur

3. 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

4. biology able to exist under more than one set of environmental conditions Compare obligate

   a facultative parasite can exist as a parasite or a saprotroph

5. of or relating to a faculty

facultative

1. 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.

2. Compare obligate

Other Word Forms

• facultatively adverb
• nonfacultative adjective

Word History and Origins

Origin of facultative¹

First recorded in 1820-25; from French facultative (feminine) “conveying or granting a right or power,” from faculté “knowledge, learning, physical or moral capacity,” ultimately from Latin facultāt-, the stem of facultās (originally a doublet of the noun facilitās “ease, ease of performance or completion, facility”) “ability, power, capacity” + -ative adjective suffix; see faculty ( def. ), -ive ( def. )

Example Sentences

"Certain temperature conditions may foster all-female populations, which can be overcome through facultative parthenogenesis," he said.

Read more on Salon

Some species, termed facultative parthenogens, alternate between sexual and asexual reproduction.

Read more on Scientific American

On the issue of facultative reinsurance, whereby it insures bundles of risk in a job lot, Swiss Re said it expected to finalise a policy for the oil and gas sector in 2023.

Read more on Reuters

The dragon’s birth, which came during a study of fertility, was said to result from a special type of parthenogenesis, called facultative parthenogenesis.

Read more on Washington Post

It’s known as “facultative parthenogenesis,” said scientists at the zoo, meaning “she reproduced without contribution from a male.”

Read more on Washington Post