- chestnutAn edible nut (technically a fruit) of the Spanish chestnut or sweet chestnut tree (Castanea sativa); also (chiefly preceded by a descriptive word), a nut from a related shrub or tree; or a similar nut from an unrelated plant.
- castanetA single handheld percussion instrument consisting of a pair of concave shells or shell-shaped parts joined on one edge by string.
- castalaginAn ellagitannin found in oak and chestnut wood.
- castaneousHaving the colour of a chestnut; chestnut-coloured.