noun see: tome Date: 1845 any of a class (Bacillariophyceae) of minute planktonic unicellular or colonial algae with silicified skeletons that form ~aceous earth
DIATOM
Meaning of DIATOM in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012