1. lives on or in another organism and feeds off it, typically causing harm to the host
Usage: third person singular present tense; British spelling

Examples

• The tick parasitises mammals by feeding on their blood.
• This fungus parasitises oak trees and weakens their immune systems.
• The wasp parasitises caterpillars by laying eggs inside them.
• The mistletoe parasitises the host tree’s nutrients and water.
• This species of bird parasitises other birds’ nests.
• The virus parasitises healthy cells to reproduce.