PARASITISM
parasitism
(noun) the relation between two different kinds of organisms in which one receives benefits from the other by causing damage to it (usually not fatal damage)
Source: WordNet® 3.1
Etymology
Noun
parasitism (usually uncountable, plural parasitisms)
(ecology) Interaction between two organisms, in which one organism (the parasite) benefits and the other (the host) is harmed.
(figuratively) A similar interaction between people.
Source: Wiktionary
Par"a*si`tism, n. Etym: [Cf. F. parasitisme.]
1. The state or behavior of a parasite; the act of a parasite. "Court
parasitism." Milton.
2. (Bot. & Zoöl.)
Definition: The state of being parasitic.
Source: Webster’s Unabridged Dictionary 1913 Edition