D defs.my
Entry 1 sense Webster, 1913

Laurentian

/lä-rĕnʹshən/ · Lau·ren·tian · IPA /lɑˈɹɛnʃən/
01 a. Pertaining to, or near, the St. Lawrence River; as, the Laurentian hills.
  1. 1.
    Pertaining to, or near, the St. Lawrence River; as, the Laurentian hills.
Phrases & compounds
Laurentian period — the lower of the two divisions of the Archæan age; -- called also the Laurentian.