[dahy-uh-tuh
m -tom] 
| any of numerous microscopic, unicellular, marine or freshwater algae of the phylum Chrysophyta, having cell walls containing silica. |
| di·a·tom (dī'ə-tŏm') n. Any of various microscopic one-celled or colonial algae of the class Bacillariophyceae, having cell walls of silica consisting of two interlocking symmetrical valves. [New Latin diatoma, from Greek diatomos, cut in half, from diatemnein, to cut in half : dia-, dia- + temnein, to cut; see tem- in Indo-European roots.] |