Definition of Cambrian in US English:

Cambrian

adjective

  • 1(chiefly in names or geographical terms) Welsh.

    ‘the Cambrian Railway’
    • ‘The Cambrian Railways were absorbed by the Great Western Railway on 1 January 1922.’
    • ‘The Cambrian mountains, almost overwhelmed by conifer plantations, are growing a new kind of forest.’
    • ‘In 1865 The Cambrian Railway company was formed through an amalgamation of smaller companies.’
    • ‘Martin Wright from Ponterwyd has loved the Cambrian Mountains since he was a boy.’
  • 2Geology
    Relating to or denoting the first period in the Paleozoic era, between the end of the Precambrian eon and the beginning of the Ordovician period.

    The Cambrian lasted from about 570 million to 510 million years ago and was a time of widespread seas. It is the earliest period in which fossils, notably trilobites, can be used in geological dating

    • ‘Now that science has progressed and more data becomes available, it is clear that the Cambrian explosion is well explainable in Darwinian terms.’
    • ‘Others have suggested that there is nothing unusual about Cambrian faunas in terms of their flexibility or disparity.’
    • ‘Precambrian rocks are those formed before the beginning of the Cambrian period, about 590 million years ago.’
    • ‘He also cites the puzzling Cambrian explosion, a spectacular sunburst of marine animals 540 million years ago that laid the foundations of all subsequent evolution.’
    • ‘Sedgwick began fieldwork at Barmouth in north Wales in 1831 where he established the order of local rocks and gave the name Cambrian to the oldest fossiliferous strata.’
    1. 2.1as noun the Cambrian The Cambrian period or the system of rocks deposited during it.

Origin

Mid 17th century: from Latin Cambria ‘Wales’, variant of Cumbria, from Welsh Cymry ‘Welshman’ or Cymru ‘Wales’.

Pronunciation

Cambrian

/ˈkambrēən//ˈkæmbriən/