ENGLISH
REFERENCE

kidney

n.
US //ˈkɪdni// UK //kˈɪdni// kid·ney
  1. 1 body organ (n.)
    B2 Upper Intermediate Medicine

    one of the two organs in your lower back that filter waste from your blood to make urine.

    either of a pair of bean-shaped organs in the abdominal cavity that filter blood and excrete waste as urine.

    Example

    Drinking plenty of water helps your kidneys function properly and stay healthy.

    Example

    The patient was diagnosed with chronic kidney disease after routine blood tests revealed a significant decline in filtration efficiency.

  2. 2 food (n.)
    B2 Upper Intermediate Cooking

    the kidney of an animal, such as a cow or pig, eaten as food.

    the organ of an animal used as an edible variety of offal.

    Example

    Steak and kidney pie is a traditional dish in British pubs.

    Example

    The chef prepared a classic devilled kidney dish, sautéing the meat with a spicy mustard sauce and serving it on toasted brioche.
    • offal
  3. 3 type or character (n.)
    C2 Proficiency Literary Archaic

    a person's character, nature, or kind.

    a person's temperament, disposition, or specific type. Usually used in the phrase 'of that kidney'.

    Example

    He was a man of a very different kidney than his brother.

    Example

    The headmaster was a stern fellow, and he expected his staff to be of the same disciplined kidney.

    Usage

    Typically appears in the idiomatic construction 'of that kidney' or 'of the same kidney'.
Origin

From Middle English kedney, kydeney, from earlier kidnēre, kidenēre (“kidney”), of obscure origin and formation. Probably a compound consisting of Middle English kid, quid (“belly, womb”), from Old English cwiþ, cwiþa (“belly, womb, stomach”) + Middle English nēre (“kidney”), from Old English nēora (“kidney”), from Proto-West Germanic neurō, from Proto-Germanic neurô (“kidney”), from Proto-Indo-European negʷʰr- (“kidney”). If so, then related to dialectal English near (“kidney”), Scots nere, neir (“kidney”), Saterland Frisian Njuure (“kidney”), Dutch nier (“kidney”), German Niere (“kidney”), Danish nyre (“kidney”), Norwegian nyre (“kidney”), Swedish njure (“kidney”), Ancient Greek νεφρός (nephrós). Alternate etymology traces the first element to Old English cydde (“sack, belly, scrotum”), from Proto-Germanic kuddijā (“sack”) as the terms for testicle and kidney were often interchangeable in Germanic (compare Old High German nioro (“kidney", also "testicle”), Old Swedish vig-niauri (“testicle”)). More at codpiece.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

Related words

Last updated June 19, 2026