Entry 1 sense Webster, 1913 Vierkleur · Vier·kleur · IPA /ˈfɪɹklɜɹ/ 01 n. The four-colored flag of the South African Republic, or Transvaal, -- red, white, blue, and green. 1. The four-colored flag of the South African Republic, or Transvaal, -- red, white, blue, and green.