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

Last August 2, in his only year with the Raiders, Johnson sustained a fractured fibula after colliding with teammate Maxx Crosby during a practice. —Barry Jackson, Miami Herald, 11 Mar. 2026

In Week 12, Jones fractured his left fibula. —Daniel Popper, New York Times, 5 Mar. 2026

In addition to a torn ACL and various tibia and fibula fractures, Vonn also broke her right ankle. —Mia Fishman, CNN Money, 23 Feb. 2026

Ivey shattered the fibula in his left leg on New Year’s Day in 2025, a gruesome injury that required multiple surgeries and months of rehabilitation. —Julia Poe, Chicago Tribune, 22 Feb. 2026

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