Chestnut and Horse chestnut

Chestnut noun - An idea or expression that has been used by many people.

Horse chestnut and chestnut are semantically related. In some cases you can use "Horse chestnut" instead a noun "Chestnut".

Horse chestnut noun - Tree having palmate leaves and large clusters of white to red flowers followed by brown shiny inedible seeds.

Chestnut and horse chestnut are semantically related. You can use "Chestnut" instead a noun phrase "Horse chestnut".