exogenous

American  

[ek-soj-uh-nuhs] / ɛkˈsɒdʒ ə nəs /

adjective

1. originating from outside; derived externally.

2. Botany.

   1. (of plants, as the dicotyledons) having stems that grow by the addition of an annual layer of wood to the outside beneath the bark.

   2. pertaining to plants having such stems.

   3. belonging to the exogens.

3. Pathology. (of a disease) externally caused rather than resulting from conditions within the organism.

4. Biochemistry. of or noting the metabolic assimilation of proteins or other metabolites, the elimination of nitrogenous catabolites being in direct proportion to the amount of metabolites taken in.

5. Geology. exogenetic.

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exogenous British  

/ ɛkˈsɒdʒɪnəs /

adjective

1. having an external origin

2. biology

   1. developing or originating outside an organism or part of an organism

   2. of or relating to external factors, such as light, that influence an organism

3. psychiatry (of a mental illness) caused by external factors

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exogenous Scientific  

/ ĕk-sŏj′ə-nəs /

1. Originating or produced from outside an organism, tissue, or cell.

2. Compare endogenous

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Other Word Forms

• exogenism
  noun
• exogenously
  adverb

Etymology

Origin of exogenous

First recorded in 1820–30; exo- + -gen + -ous

Explanation

Something that's exogenous comes from somewhere else, from outside. If your village practices exogenous marriage, you'll need to find a mate from another village, one outside your own. Exogenous is the opposite of endogenous. If your village traditions favor endogenous marriage, you’ll marry somebody from your own village. In biology and medicine, especially psychiatry, the word exogenous is used to describe outside factors, something that originates from outside the organism. When you're identifying causes of disease, toxins in your environment would be exogenous causes (they come from outside you), while genetic predisposition (something inside you) would be considered an endogenous cause.

Example Sentences

“That’s now exogenous; it isn’t going to change for a while,” he says.

From Barron's • Apr. 3, 2026

For patients with severe cases that are difficult to control with exogenous insulin, doctors can perform islet cell transplants, which include beta cells.

From Science Daily • Mar. 2, 2026

He said while the company absorbed an exogenous shock linked to tariffs, which “disproportionately affecting ad spend from our top retail advertisers, this quarter also underscored where we need to move faster.”

From MarketWatch • Feb. 13, 2026

The effect, barring some history-altering exogenous circumstance, has almost certainly been to push the war’s conclusion further into the future.

From The Wall Street Journal • Jan. 1, 2026

Liber, lī′ber, n. the bast or inner bark of exogenous plants: a book.

From Chambers's Twentieth Century Dictionary (part 2 of 4: E-M) by Various

Related Words

• external