ruddle

/ˈrʌdəl/
noun
  1. A red or brownish-red mineral (often ochre) used as a pigment or for marking sheep.
    • The farmer used ruddle to mark the sheep that had been counted.
    • She bought a bag of ruddle to color the garden paths a warm red.
    • Ancient cave paintings were made with ruddle mixed with animal fat.
Synonyms
verb
  1. To mark or color with ruddle.
    • The shepherd ruddled the lambs before the fair.
    • In the old days, farmers would ruddle their sheep to show ownership.
    • They ruddle the fence posts to protect the wood from weather.