femur
Americannoun
plural
femurs, femora-
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.
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Zoology. a corresponding bone of the leg or hind limb of an animal.
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Entomology. the third segment of the leg of an insect (counting from the base), situated between the trochanter and the tibia.
noun
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Nontechnical name: thighbone. the longest thickest bone of the human skeleton, articulating with the pelvis above and the knee below
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the corresponding bone in other vertebrates
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the segment of an insect's leg nearest to the body
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
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Life Science: Human Anatomy and Physiology
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Human Anatomy and Physiology - Middle School
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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.
Researchers confirmed that the fossil belonged to a juvenile by examining growth patterns in a thin section of its femur bone.
From Science Daily • Apr. 1, 2026
In his office, where his mayor's chain is displayed alongside a polar bear femur, Terje Aunevik echoed that sentiment.
From Barron's • Feb. 19, 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
A small section of hip was left of the torso, and there was enough bone in the femur and the hip for pathologists to match them together, confirming it was the same individual.
From BBC • Jan. 31, 2026
“Coxa, trochanter, femur, patella, tibia, metatarsus, and tarsus.”
From "Charlotte's Web" by E.B. White
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.
