Primordial

a. [Lat. primordialis, from primordium, the first beginning, from primus, first, and ordiri, to begin a web, to begin; Fr., Pr., Sp., & Pg. primordial, It. primordiale.]

1. First in order; original; existing from the beginning; of earliest origin. “The primordial facts of our intelligent nature.” Sir W. Hamilton.
2. (Geol.) Of, or pertaining to, the lowest beds of the Silurian period, corresponding to the Potsdam period in American geology; — so applied by Barrande. Dana.
3. (Physiol.) (a.) Pertaining to or being the original or earliest materials in the growth of an individual or organ. (b.) Marking the earliest formed organ or condition; as, a primordial leaf, or that first after the cotyledon.