animalcule

plural animalcules

1. historicalmedicineA sperm cell or spermatozoon; also, the embryo that was formerly thought to be contained inside a spermatozoon in a fully developed state.First known use 17th c.

   [Antonie van] Leeuwenhoek's most mysterious finding was yet to come, however. Inside the animalcules in the thickest part of the semen he saw / all manner of great and small vessels, so various and so numerous that I do not doubt that they be nerves, arteries and veins. …

   2001, David M. Friedman, “The Gear Shift”, in A Mind of Its Own: A Cultural History of the Penis, New York, N.Y.: The Free Press, →ISBN, page 76

2. archaicbiologyA microscopic aquatic animal, including protozoa and rotifers.First known use 17th c.

   If we are part of nature, then we are synonymous with it at the metaphysical level, every bit as much as the first all-but-inorganic animalcules that ever formed a chain of themselves in the blow hole of a primordial sea vent.

   2011, John Jeremiah Sullivan, “La·hwi·ne·ski: Career of an Eccentric Naturalist”, in Pulphead, New York, N.Y.: Farrar, Straus and Giroux, →OCLC, pages 212–213

3. obsoleteA small animal.First known use 16th–20th c.

   Is it not evident that if a parasitic animalcule desired to call its attention it would sink a hole in its shell and so stimulate its sensory apparatus?

   1928 February 25 – March 3, Arthur Conan Doyle, “When the World Screamed”, in The Professor Challenger Stories […], London: John Murray, […], published [1952], →OCLC, page 555

   1 more example

   Why, there is not a Man, or a Thing, now alive but has tools. The basest of created animalcules, the Spider itself, has a spinning-jenny, and warping-mill, and power-loom within its head: […]

   1831, Thomas Carlyle, “Pause”, in Sartor Resartus: The Life and Opinions of Herr Teufelsdröckh. […], London: Chapman and Hall, […], →OCLC, 2nd book, page 137