noun
paramecium; slipper animalcule
Refers to Paramecium species, especially Paramecium caudatum. Common in biology contexts.
池の水を顕微鏡で見ると、ゾウリムシが泳いでいた。
When I looked at the pond water under a microscope, paramecia were swimming.
Standard katakana spelling; the word is usually written in kana.
Kanji spelling; rarely used in practice.
From 草履 (zōri, 'straw sandals') + 虫 (mushi, 'insect, bug'), named for its slipper-like shape.