SINCE 1828

An Encyclopædia Britannica Company

facultative

adjective fac·ul·ta·tive \ ˈfa-kəl-ˌtā-tiv , British -tə-tiv \

Updated on: 28 Feb 2018

Definition of facultative

1 a : of or relating to the grant of permission, authority, or privilege

facultative legislation

b : optional

2 : of or relating to a mental faculty

3 a : taking place under some conditions but not under others

facultative diapause

b : exhibiting an indicated lifestyle under some environmental conditions but not under others

facultative anaerobes

—

facultatively

adverb

Origin and Etymology of facultative

borrowed from French & New Latin; French facultatif, borrowed from New Latin facultātīvus, from Medieval Latin facultāt-, facultās "ability, power, authority, privilege, right" (Latin, "ability, power") + Latin -īvus -ive — more at faculty

NEW! Time Traveler

First Known Use: 1820

in the meaning defined at sense 1a

See Words from the same year

Medical Dictionary

facultative

adjective fac·ul·ta·tive \ ˈfak-əl-ˌtāt-iv \

medical Definition of facultative

1 : taking place under some conditions but not under others

facultative parasitism

2 : exhibiting an indicated lifestyle under some environmental conditions but not under others

facultative anaerobes

—

facultatively

adverb

Learn More about facultative

See words that rhyme with facultative Nglish: Translation of facultative for Spanish speakers Britannica English: Translation of facultative for Arabic speakers

Seen and Heard

What made you want to look up facultative? Please tell us where you read or heard it (including the quote, if possible).

show

WORD OF THE DAY

mollycoddle

play

to treat with excessive attention

BROWSE DICTIONARY

facty

facula

facultative

facultative referendum

faculty

Test Your Vocabulary

April 2018 Words of the Day Quiz

Which is the best synonym of traduce?

Name That Thing

Test your visual vocabulary with our 10-question challenge!

TAKE THE QUIZ

SCRABBLE® Sprint

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Words at Play

alt-5ae23d5d250bd

'Rather Than': Is It a Conjunction or Preposition?

It's both, and here's why.

alt-5ae227cf365c4

‘Magnate’ and ‘Magnet’: Poles Apart

This is kind of a Big Deal

All the Hits

8 obscure words for bodily harm

alt-5adf93a49b0b2

The Fossil Encased in "Case In Point"

"In point" only lives in this phrase.

Ask the Editors

2017 Word of the Year: Behind the Scenes

How we chose 'feminism'

video-title-words-of-the-year-1066

Words of the Year: 1066

Or, Why Pig Meat is Called 'Pork' and Cow Meat is Called 'Beef'

video-literally

Literally

How to use a word that (literally) drives some people nuts.

video-his-or-her

Is Singular 'They' a Better Choice?

The awkward case of 'his or her'

Word Games

rain-on-rainbow-umbrella

April 2018 Words of the Day Quiz

The rhyming verb edition.

Take the quiz

Odd Habits and Quirks Quiz

Test your knowledge of strange human behaviors.

Take the quiz

Name That Thing

Name That Thing

Test your visual vocabulary with our 10-question challenge!

Take the quiz

SCRABBLE® Sprint

SCRABBLE® Sprint

SCRABBLE® fans, sharpen your skills!

Play the game