The Collaborative International Dictionary
Chay root
Chay root \Chay" root`\ [Tamil sh[=a]ya.] The root of the Oldenlandia umbellata, native in India, which yieds a durable red dyestuff. [Written also choy root.]
Wiktionary
chay root
n. The root of the ''Oldenlandia umbellata'', native to India, which yields a durable red dyestuff.