Definition of animalcule in English:

animalcule

noun

archaic
  • A microscopic animal.

    • ‘Three weeks later, on April 24, 1676, he discovered an incredible number of very little animalcules, marking the first sighting of bacteria.’
    • ‘Looking at these samples with his microscope, Leeuwenhoek reported how in his own mouth: ‘I then most always saw, with great wonder, that in the said matter there were many very little living animalcules, very prettily a-moving.’’
    • ‘It is in this context that the idea of an evaluative classification came into its own, a progressive scale of nature leading from the lowest animalcules to the glory of mankind.’
    • ‘Since animalcules were visible only under a microscope, most of the city's residents had neither seen nor heard of them.’
    • ‘The lowest plant, or animalcule, feeds, grows, and reproduces its kind.’
    • ‘Leeuwenhoek tried ingenious ways to estimate the size of his animalcules.’

Origin

Late 16th century: from modern Latin animalculum, from animal ‘an animal’ + -cule.

Pronunciation

animalcule

/ˌanɪˈmalkjuːl/