Microfilariae

Part of speech: noun

Definitions

1. The immature young of certain parasitic threadlike worms, which circulate in the blood of an infected host before maturing
2. Tiny larval forms of filarial roundworms that live in the bloodstream and are often spread by biting insects
3. Early-stage larvae of filarial nematodes, found in the blood or skin of infected humans and animals

Etymology: "Microfilariae" is the plural of "microfilaria," a term for the tiny larval worms of certain parasitic nematodes that circulate in a host's blood. The singular combines "micro-," from the Greek "mīkrós," meaning small, with "filaria," the name for the thread-like nematode worms themselves. Those worms, the word's second half, take their name from the Latin "filum," meaning thread, which describes their long, slender bodies. The compound is a plain piece of scientific construction rather than an ancient coinage. Greek "mīkro-" and Latin-derived "filaria" were brought together in modern medical and zoological Latin to name a stage of the parasite's life cycle that could be seen only under a microscope, so the word describes exactly what the observer saw: a threadworm too small to see without magnification.