1.(Bot.) Derived from or originating outside; pertaining to, or having the character of, an exogen; the opposite of endogenous.
2.(Bot.) Growing by addition to the exterior; growing by addition of a new external layer of cells on the surface just beneath the bark; of plants.
3.(Anat.) Growing from previously ossified parts; opposed to autogenous.
4.(Med.) Caused by factors from outside the body, rather than from an abnormality of internal functions; of illness.
5.(Biol., Biochem.) Not synthesized within the organism; absorbed or assimilated from outside the organism.
