Webster’s Revised Unabridged Dictionary · 1913
Cinnamic
Cin·nam′ic (sĭn·năm′ĭk), a. [From Cinnamon.] (Chem.) Pertaining to, or obtained from, cinnamon.
Cinnamic acid (Chem.), a white, crystalline, odorless substance. C6H5. C2H2C2H2.CO2H, formerly obtained from storax and oil of cinnamon, now made from certain benzene derivatives in large quantities, and used for the artificial production of indigo.