WordReference Random House Unabridged Dictionary of American English © 2026
pe′ri•od′ic sys′tem
(pēr′ē od′ik, pēr′-),USA pronunciation [Chem.]
- Chemistrya system of classification of the elements based on the periodic law.
- 1870–75
'periodic system' also found in these entries (note: many are not synonyms or translations):