femurs

IPA/ˈfiː.mər/
IPA/ˈfiː.mɚ/

femurs — noun

  • femurssingular
  • femursesplural

1. The large, thick bone that forms the framework of the upper leg, running from th

1.nounB2
Definition

The large, thick bone that forms the framework of the upper leg, running from the hip joint down to the knee and supporting the body's weight when a person stands or walks.

Example

The doctor showed Cyrus the X-ray and noted that both femurs looked healthy.

plural form: both femurs

After falling from her horse, Yumi spent six weeks recovering from a broken femur.

countable noun: a broken femur

Common collocations
  • broken femur
  • fractured femur
  • left / right femur
  • femur bone
Synonyms
  • thigh bone

    plain everyday term; less precise than 'femur' but used in non-medical conversation

Grammar Patterns

the femur

a femur

both femurs

Usage Note

In everyday medical English the plural is usually "femurs"; the Latin plural "femora" is rare and mostly limited to academic anatomy writing.

Common Mistakes

She broke her thigh.
She broke her femur.
'thigh' is the whole upper leg, not the bone inside it.
The femur are the longest bone in the body.
The femur is the longest bone in the body.
'femur' is a singular countable noun and takes a singular verb.

Word family

  • femur
    nounB2
  • femoral
    adjectiveC1
  • femoral
    nounC1

Synonym discussion

Sense: noun/1

"Femur" is the formal anatomical term for the single long bone inside the upper leg. "Thigh bone" is the everyday equivalent — less precise but appropriate in casual conversation (e.g. "I think I bruised my thigh bone"). "Thigh" refers to the whole fleshy part of the upper leg, including muscles, skin, fat, and the femur inside it. Use "femur" in medical or biology contexts; use "thigh" when talking about the outer part of the leg. For example, a physiotherapist might say "Your femur is well aligned" but a friend might say "My thigh is sore from all that running."

femur ↗thigh bonethigh ↗

Common collocations

Nouns

Phrases

  • fracture of the femur
  • head of the femur
  • neck of the femur

Prepositions

  • of the femur

Etymology

LatinEnglish

From Latin "femur" meaning 'thigh'. The word entered English directly from Latin as a medical term. The English plural "femurs" has largely replaced the classical Latin plural "femora" in modern usage.

First known use

1666

1666, in the meaning defined at sense 1