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basal

American  
[bey-suhl, -zuhl] / ˈbeɪ səl, -zəl /

adjective

  1. of, at, or forming the base.

  2. forming a basis; fundamental; basic.

  3. Physiology.

    1. indicating a standard low level of activity of an organism, as during total rest.

    2. of an amount required to maintain this level.

  4. Medicine/Medical. serving to induce a preliminary or light anesthesia prior to total anesthetization.


basal British  
/ ˈbeɪsəl /

adjective

  1. at, of, or constituting a base

  2. of or constituting a foundation or basis; fundamental; essential

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

  • basally adverb
  • prebasal adjective

Etymology

Origin of basal

First recorded in 1820–30; base 1 + -al 1

Explanation

Something that's basal forms the base or the bottom layer of an object. The basal leaves on a plant are connected to the lowest section of its stem. In medicine, the word basal describes structures that are located at the base of some major organ or other body part. Basal ganglia, for example, are found at the base of the brain in humans, and a basal cell is at the deepest part of the skin. Basal comes from the word base, from the Latin basis, "foundation," via the Greek basis, "step or pedestal."

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Vocabulary lists containing basal

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.

In contrast, basal subtype tumors are more disorganized and aggressive, and they are often resistant to chemotherapy.

From Science Daily • Mar. 3, 2026

Non-melanoma cancers like basal and squamous cell are more common but usually less likely to spread or be fatal, he said.

From BBC • Dec. 30, 2025

They tracked each patient's next diagnosis of basal cell carcinoma or cutaneous squamous cell carcinoma.

From Science Daily • Oct. 20, 2025

BCC begins with abnormal growth of basal cells, which produce new skin cells when old ones die, on the outermost layer of the skin.

From Salon • Sep. 2, 2025

The centrioles, which hoist the microtubules on which chromosomes are strung for mitosis, are similar separate creatures; when not busy with mitosis, they become the basal bodies to which cilia are attached.

From "The Lives of a Cell" by Lewis Thomas