The Tough Brown Seeds of the Horse Chestnut Tree
This page is the CodyCross answer for the clue below from Prehistory, Group 1251, Puzzle 4 (Cave Paintings).
Question is: The Tough Brown Seeds of the Horse Chestnut Tree
and the answer is: CONKERS
Word Meaning:
CONKERS — (British, games) A game for two players in which the participants each have a horse-chestnut (known as a "conker") suspended from a length of string, and take turns to strike their opponent's conker with their own with the object of destroying the opponent's conker before their own is destroyed.
Definitions from Wiktionary.