Crossword clues for the word: DIATOMS The word DIATOMS has appeared as an answer to at least 4 crossword clues on different crossword puzzles. Crossword clues for DIATOMS Showing 1 to 4 of 4 results Clue(s) """They're at the bottom of the food chain,"" Tom said swimmingly (7)" Certain algae Freshwater algae Microscopic algae.