fibula

noun

fib·​u·​la ˈfi-byə-lə 

plural fibulae ˈfi-byə-lē  -lī  or fibulas

1

: the outer and usually smaller of the two bones between the knee and ankle in the hind or lower limbs of vertebrates

2

: a clasp resembling a safety pin used especially by the ancient Greeks and Romans

fibular

ˈfi-byə-lər 

adjective

Illustration of fibula

• fibula 2

Examples of fibula in a Sentence

Recent Examples on the Web

The findings contained fossils of vertebrae, ribs, humerus, ulna, fibula and foot bones. —Julia Jacobo, ABC News, 2 Sep. 2025

The boy had suffered many injuries that included an arterial bleed in his right wrist and calf wounds that made his tibia and fibula visible, according to Fox News. —Ingrid Vasquez, People.com, 26 Aug. 2025

To his credit, running back Isiah Pacheco worked hard to return to the Chiefs as quickly as possible last season after being sidelined by a fractured fibula in Week 2. —Pete Grathoff, Kansas City Star, 23 Aug. 2025

The star pass rusher was wreaking havoc on the NFL last season before fracturing his tibia and fibula in Week 6. —Austin Mock, New York Times, 21 Aug. 2025

Word History

Etymology

Latin, pin, clasp; akin to Latin figere to fasten

First Known Use

1578, in the meaning defined at sense 1

Kids Definition

fibula

noun

fib·​u·​la ˈfib-yə-lə 

plural fibulae -ˌlē 

-ˌlī

or fibulas

: the outer and usually the smaller of the two bones between the knee and ankle of the hind or lower limb

fibular

-lər 

adjective

Medical Definition

fibula

noun

fib·​u·​la ˈfib-yə-lə 

plural fibulae

-lē also -ˌlī

or fibulas

: the outer or postaxial and usually the smaller of the two bones of the hind or lower limb below the knee that is the slenderest bone of the human body in proportion to its length, articulates above with the external tuberosity of the tibia and below with the talus, and has its lower end forming the external malleolus of the ankle

called also calf bone

fibular

-lər 

adjective