kidney

IPA/ˈkɪdni/
KK[kˈɪdni]IPA/ˈkɪdni/

kidney — noun

  • kidneysingular
  • kidneysplural

1. One of two bean-shaped body parts inside your body that clean waste from your bl

1.nounB1
Definition

One of two bean-shaped body parts inside your body that clean waste from your blood and turn it into urine.

Example

A healthy kidney filters waste from the blood every minute of the day.

The doctor told Noor that her kidney function had improved after the new treatment.

collocation: kidney function

Common collocations
  • kidney function
  • kidney failure
  • kidney disease
  • kidney transplant
  • kidney stone
  • donate a kidney
  • kidney damage
Synonyms
  • renal organ

    medical/technical term; rarely used in everyday speech

Grammar Patterns

the kidneys

a kidney

Usage Note

Frequently used in the plural (the kidneys) when referring to the pair as a system. Common in medical contexts involving disease, donation, and surgery.

Common Mistakes

He injured his kidney in an accident.
He injured his kidney in a car crash.
'kidney' is the correct word for the organ; do not confuse with 'liver' (a different organ on the opposite side of the body).

2. An animal's kidney prepared as food, often cooked in pies, stews, or grilled.

2.nounB1
Definition

An animal's kidney prepared as food, often cooked in pies, stews, or grilled.

Example

In Britain, steak and kidney pie is a classic dish found in many pubs.

collocation: steak and kidney pie

Wei grilled the lamb kidneys over charcoal and served them with fresh herbs.

collocation: lamb kidneys

Common collocations
  • steak and kidney pie
  • lamb kidneys
  • pork kidneys
  • kidney stew
  • grilled kidneys
Synonyms
  • offal

    broader term covering all animal internal organs used as food; not specific to kidneys

  • organ meat

    general term for edible internal organs; broader in meaning

Grammar Patterns

lamb / pork / beef kidneys

kidney + dish / pie / stew

Usage Note

In English cuisine, animal kidneys are commonly used in pies and stews. In East Asian cooking, they are often stir-fried or grilled. The type of animal (lamb, pork, beef) is usually specified.

Word family

Synonym discussion

Sense: noun/1

Kidney and liver are both internal organs that filter substances from the blood, but they have different functions and locations in the body. 'Kidney' is the everyday English word that learners encounter in health class and at the doctor's office. 'Renal organ' is the technical medical term (from Latin renes) and appears almost exclusively in clinical writing or specialist discussion — you would not use it in casual conversation about a family member's health. 'Liver' is the organ that processes nutrients and removes toxins, while the kidneys filter waste to produce urine. A useful distinction: a doctor might say 'renal function' when discussing lab results, but will say 'kidney' when talking directly to a patient. For example: 'The blood test showed excellent kidney function' sounds natural; 'the blood test showed excellent renal organ function' sounds overly technical.

kidney ↗renal organliver ↗

Etymology

Old EnglishMiddle EnglishEnglish

The word 'kidney' comes from Middle English 'kidnei', which was formed by combining an Old English word for 'womb' or 'belly' (perhaps related to 'cud' meaning what is chewed) with 'ey' (meaning 'egg'), referring to the organ's egg-like shape. The spelling and pronunciation have changed gradually over the past 700 years, but the reference to a bean-shaped organ has remained constant. Modern medical terms for kidney-related matters (like 'renal' and 'nephro-') come from Latin and Greek, not from this Germanic root.