Biotrophic is a related term of biotroph.

In biology|lang=en terms the difference between biotrophic and biotroph

is that biotrophic is (biology) describing a parasite that needs its host to stay alive while biotroph is (biology) any parasite that cannot survive in a dead host and therefore keeps it alive.

As an adjective biotrophic

is (biology) describing a parasite that needs its host to stay alive.

As a noun biotroph is

(biology) any parasite that cannot survive in a dead host and therefore keeps it alive.