facultative

adjective

fac·​ul·​ta·​tive ˈfa-kəl-ˌtā-tiv 

 British  -tə-tiv

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

Examples of facultative in a Sentence

Recent Examples on the Web

Unlike the Queensland lungfish, which is a facultative air-breather, the South American lungfish must breathe air to survive. —Scott Travers, Forbes, 15 Sep. 2024

This is all speculative, but the hypothesis that Dudgeon is playing with is that, for some vertebrates, facultative parthenogenesis might be like the evolutionary equivalent of a Hail Mary pass. —Byrd Pinkerton, Vox, 12 June 2024

Discovery of facultative parthenogenesis in a new world crocodile Biology Letters. —Cody Cottier, Discover Magazine, 22 Mar. 2024

Advertisement Booth wanted to prove that the stillborn crocodile was created through facultative parthenogenesis. —Kyle Melnick, Washington Post, 9 June 2023

Advertisement Most facultative parthenogenesis discoveries have occurred in the past two decades as DNA testing has evolved. —Kyle Melnick, Washington Post, 9 June 2023

This occurred through facultative parthenogenesis, a form of asexual reproduction. —Kyle Melnick, Washington Post, 9 June 2023

This type of reproduction is called facultative parthenogenesis and has been documented before in animals including birds, non-avian reptiles, specifically lizards and snakes, and certain types of fish, including sharks and stingrays. —Emily Deletter, USA TODAY, 7 June 2023

The problem with that idea, Kronauer explained, is that nobody has ever observed in the wild what should be an essential, early step of the process: free-living, facultative social parasites living in isolation from their close relatives. —Viviane Callier, Quanta Magazine, 8 May 2023

Word History

Etymology

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

First Known Use

1820, in the meaning defined at sense 1a

Medical Definition

facultative

adjective

fac·​ul·​ta·​tive ˈfak-əl-ˌtāt-iv 

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