conker

Etymology 1

From 19th-century dialect conker (“snail-shell”); the game of conkers was originally played using snail-shells; from conch + -er or a variant of conquer.

noun

1. (Britain) A horse chestnut, used in the game of conkers.
   His bald spot gleams like a burnished conker. 2006, Peter Godwin, When a Crocodile Eats the Sun: A Memoir of Africa

Etymology 2

noun

1. Alternative form of kankar
   The roads are not exceeded by any throughout India; hard conker pounded, makes them as level as a table. 1833, Edward C. Archer, Tours in Upper India and in Parts of the Himalaya Mountains, page 89