What is the meaning of basal?

adjective

• Especially of leaves; located at the base of a plant or stem; especially arising directly from the root or rootstock or a root-like stem.
  • usage: "basal placentation"; "radical leaves"
  • synonyms: radical
• Serving as or forming a base.
  • usage: "the painter applied a base coat followed by two finishing coats"
  • synonyms: base
• Of primary importance.
  • synonyms: primary