naturalist

One versed in natural history, especially in zoology or botany.

One who believes in and follows the tenets of naturalism.

One who understands natural causes; one who is versed in natural science or philosophy; specifically, one who is versed in or devoted to natural history; in the most restricted sense, a zoölogist or botanist.

One who holds the theological theory or doctrine of naturalism.

One versed in natural science; a student of natural history, esp. of the natural history of plants or animals; a botanist or zoologist.

One who holds or maintains the doctrine of naturalism in religion.

A person committed to studying nature or natural history.

A person who believes in or advocates the tenets of philosophical or methodological naturalism.

an advocate of the doctrine that the world can be understood in scientific terms

a biologist knowledgeable about natural history (especially botany and zoology)