femur
Americannoun
-
Anatomy. a bone in the human leg extending from the pelvis to the knee, that is the longest, largest, and strongest in the body; thighbone.
-
Zoology. a corresponding bone of the leg or hind limb of an animal.
-
Entomology. the third segment of the leg of an insect (counting from the base), situated between the trochanter and the tibia.
noun
-
Nontechnical name: thighbone. the longest thickest bone of the human skeleton, articulating with the pelvis above and the knee below
-
the corresponding bone in other vertebrates
-
the segment of an insect's leg nearest to the body
Other Word Forms
Noun Inflected Forms
Etymology
Origin of femur
1555–65; < Latin: thigh
Explanation
Your femur is the large bone inside your thigh. The femur is the strongest bone in the human body. In between your knee and hip joints is your femur, the only bone in the upper part of your leg. The femur isn't just strong, but is also the longest of your bones. Four-legged animals have femurs as well. When this word was originally used in English, it was an architectural term. In Latin, femur means "thigh" or "thighbone."
Vocabulary lists containing femur
Human Anatomy and Physiology - High School
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
Life Science: Human Anatomy and Physiology
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
Human Anatomy and Physiology - Middle School
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
At the other end of the room, Ahmat Adam Ateib, 22, has a metal rod in his right leg, to mend a double fracture of his femur.
From Barron's • Jun. 25, 2026
The team recovered teeth, a skull, jaws, and parts of the skeleton, including a femur and an ulna.
From Science Daily • Apr. 27, 2026
"Mum tried to get to the bathroom in the night, slipped on water from a leak the hotel had already been told about, and fell. We later learned she'd broken her femur."
From BBC • Feb. 12, 2026
The ACL, which connects the shin bone to the femur, is a main stabilizing force in the knee and protects the lower leg from sliding forward.
From Los Angeles Times • Feb. 7, 2026
High cheekbones and long nose, flared at the tip like the knobs at the bottom of a femur.
From "All the Light We Cannot See" by Anthony Doerr
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
