When food is derived by killing the host, this sort of interaction is

Solution (By Examveda Team)

When food is derived by killing the host, this sort of interaction is Predation.
Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation and parasitoidism.
Predators are adapted and often highly specialized for hunting, with acute senses such as vision, hearing, or smell.