labile

adjective

la·​bile ˈlā-ˌbī(-ə)l  -bəl 

1

: readily or continually undergoing chemical, physical, or biological change or breakdown : unstable

a labile mineral

2

: readily open to change

has so labile a face that some of her scenes … rock with emotion

—Manny Farber

lability

lā-ˈbi-lə-tē 

noun

Did you know?

Labile was borrowed into English from French and can be traced back (by way of Middle French labile, meaning "prone to err") to the Latin verb labi, meaning "to slip or fall." Indeed, the first sense of labile in English was "prone to slip, err, or lapse," but that usage is now obsolete. Other labi descendants in English include collapse, elapse, and prolapse, as well as lapse itself.

Examples of labile in a Sentence

Recent Examples on the Web

The mob is aroused and labile; the lumpy cops have no control, over the situation or over themselves. —James Parker, The Atlantic, 12 Oct. 2024

Then the therapist could spend several minutes establishing a safe rapport with the patient while waiting for the memory to enter a labile state during the reconsolidation-updating window. —Bj Casey, Scientific American, 14 May 2024

There was something kinetic, something labile in his air. —Kevin Barry, The New Yorker, 8 Apr. 2024

Amid this high level of acting skill, Lindsey stood out with her wonderfully convincing gestures and facial expressions, filling out the character of the more labile younger sister with captivating verisimilitude. —Jeremy Yudkin, BostonGlobe.com, 17 July 2023

To be labile is to be unstable; in chemistry, a labile substance is easily broken down. —Maureen Stanton, Longreads, 10 Aug. 2020

On unusually chilly days, these climatically labile folks are 0 for 3. —Valerie Ross, Discover Magazine, 8 Apr. 2011

The painting, which ostensibly depicts Mary Magdalene in the reveries of devotion, is less spiritual than erotic: her interlaced fingers may be motionless, but her slight smile seems labile, indicating that Artemisia understood a woman’s sensuality from the inside out. —Rebecca Mead, The New Yorker, 28 Sep. 2020

According to the consolidation/reconsolidation hypothesis, recently acquired or reactivated memories are transformed progressively from an initially labile state into a stable form, through a protein-dependent process. —Neuroskeptic, Discover Magazine, 22 Sep. 2015

Word History

Etymology

French, from Middle French, prone to err, from Late Latin labilis, from Latin labi to slip — more at sleep

First Known Use

1603, in the meaning defined at sense 1

Medical Definition

labile

adjective

la·​bile ˈlā-ˌbīl  -bəl 

: readily or frequently changing: as

a

: readily or continually undergoing chemical, physical, or biological change or breakdown

a labile antigen

b

: characterized by wide fluctuations (as in blood pressure or glucose tolerance)

labile hypertension

labile diabetes

c

: emotionally unstable

lability

lā-ˈbil-ət-ē 

noun

plural labilities