2. (Science: geology) Of or pertaining to the lowest beds of the silurian age, corresponding to the acadian and Potsdam periods in American geology. It is called also Cambrian, and by many geologists is separated from the Silurian.
Origin: L. Primordialis, from primordium the first beginning; primus first _ ordiri to begin a web, to begin: cf. F. Primordial.