The Collaborative International Dictionary of English v.0.48:

Primordial \Pri*mor"di*al\, a. [L. primordialis, from primordium
   the first beginning; primus first + ordiri to begin a web, to
   begin: cf. F. primordial.]
   1. First in order; primary; original; of earliest origin; as,
      primordial condition. "The primordial facts of our
      intelligent nature." --Sir W. Hamilton.
      [1913 Webster]

   2. (Geol.) 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.
      [1913 Webster]

   3. (Biol.) Originally or earliest formed in the growth of an
      individual or organ; as, a primordial leaf; a primordial
      cell.
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   Primordial utricle (Bot.), the interior lining of a young
      vegetable cell.
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The Collaborative International Dictionary of English v.0.48:

Cambrian \Cam"bri*an\, a.
   1. (Geog.) Of or pertaining to Cambria or Wales.
      [1913 Webster]

   2. (Geol.) Of or pertaining to the lowest subdivision of the
      rocks of the Silurian or Molluscan age; -- sometimes
      described as inferior to the Silurian. It is named from
      its development in Cambria or Wales. See the Diagram under
      Geology.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Cambrian \Cam"bri*an\, n.
   1. A native of Cambria or Wales.
      [1913 Webster]

   2. (Geol.) The Cambrian formation.
      [1913 Webster]

WordNet (r) 3.0 (2006):

Cambrian
    adj 1: of or relating to or characteristic of Wales or its
           people or their language; "the Welsh coast"; "Welsh
           syntax" [syn: Welsh, Cambrian]
    n 1: from 544 million to about 500 million years ago; marine
         invertebrates [syn: Cambrian, Cambrian period]
    2: a native or resident of Wales [syn: Welshman, Welsh,
       Cambrian, Cymry]