Relating to or caused by ectozoa, or describing organisms that live as external parasites on other animals.
From Greek 'ekto-' (outside) + 'zoon' (animal) + '-an' (relating to); formed in the 1800s as parasitology developed as a scientific field.
The distinction between ectozoan and endozoan parasites was revolutionary for medicine—doctors realized some diseases came from creepy crawlies on your skin, not mysterious vapors!
Complete word intelligence in one call. Free tier — 50 lookups/day.