diatom (n.)youdaoicibaDictYouDict[diatom 词源字典]
1845, coined from Greek diatomos "cut in two," from diatemnein "to cut through," from dia- "through" (see dia-) + temnein "to cut" (see tome). So called because they typically appear to have been cut in half. Related: Diatomic.[diatom etymology, diatom origin, 英语词源]