exogenous

UK: /ɛkˈsɒdʒɪnəs/ US: (ek soj′ə nəs)

WordReference Random House Unabridged Dictionary of American English © 2026

ex•og•e•nous  (ek soj′ə nəs), adj. 

1. originating from outside;
   derived externally.
2. [Bot.]
   • Botany (of plants, as the dicotyledons) having stems that grow by the addition of an annual layer of wood to the outside beneath the bark.
   • Botany pertaining to plants having such stems.
   • Botany 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 (def. 1).

Also, exogenetic (for defs. 2–4).

• exo- + -gen + -ous 1820–30

ex•og′e•nism, n. 
ex•og′e•nous•ly, adv. 

Collins Concise English Dictionary © HarperCollins Publishers::

exogenous / ɛkˈsɒdʒɪnəs/ adjective

1. having an external origin
2. developing or originating outside an organism or part of an organism
3. of or relating to external factors, such as light, that influence an organism
4. (of a mental illness) caused by external factors

WordReference Random House Unabridged Dictionary of American English © 2026

ex•o•ge•net•ic  (ek′sō jə net′ik), adj. 

Also, ex•o•gen•ic  (ek′sə jen′ik), exogenous. [Geol.] arising from or relating to the surface of the earth (opposed to endogenetic).
1. Biochemistry, Botany, Pathology exogenous (defs. 2–4).

• exo- + -genetic 1870–75