Organism, Sometimes Harmful, Living Inside Another
This page is the CodyCross answer for the clue below from Greece, Group 665, Puzzle 4 (Historical Monuments).
Question is: Organism, Sometimes Harmful, Living Inside Another
and the answer is: PARASITE
Word Meaning:
PARASITE — (biology) An organism that lives on or in another organism of a different species, deriving benefit from living on or in that other organism, while not contributing towards that other organism sufficiently to cover the cost to that other organism.
Definitions from Wiktionary.