A larval stage of certain parasitic flatworms (trematodes) that has a tail-like appendage and represents a free-swimming stage in the parasite's life cycle.
From Greek kerkos meaning 'tail' plus the Latin feminine noun ending -aria. The term was coined to describe this larval form because of its distinctive tail structure.
Cercariae are one of nature's scariest mini-creatures—they swim freely in water and can burrow into your skin, which is why beaches with certain parasites are dangerous; scientists named them after their tail because that's literally the only thing holding them together.
Complete word intelligence in one call. Free tier — 50 lookups/day.