Definition from Wiktionary, the free dictionary
- (countable) A small evergreen tree native to Sri Lanka and southern India, Cinnamomum verum or Cinnamomum zeylanicum, belonging to the family Lauraceae.
- Several related trees, notably the Indonesian cinnamon (Cinnamomum burmannii) and Chinese cinnamon or cassia (Cinnamomum aromaticum or Cinnamomum cassia).
- (uncountable) A spice from the dried aromatic bark of the cinnamon tree, either rolled into strips or ground into a powder. The word is commonly used as trade name for spices made of any of the species above. The product made of Cinnamomum verum is sometimes referred to as true cinnamon.
- (countable) A yellowish-brown colour, the color of cinnamon.
Derived terms 
any of related trees in the genus Cinnamomum
cinnamon (not comparable)
- Containing cinnamon, or having a cinnamon taste.
- Of a yellowish-brown colour.
See also 
- cinnamon in Webster’s Revised Unabridged Dictionary, G. & C. Merriam, 1913
- cinnamon in The Century Dictionary, The Century Co., New York, 1911
- cinnamon at OneLook Dictionary Search