Ceylon cinnamon cey·lon·cin·namon uncommon noun 1. tropical Asian tree with aromatic yellowish-brown bark; source of the spice cinnamon SynonymscinnamonCeylon cinnamonCeylon cinnamon treeCinnamomum zeylanicum Related words Word family Ceylon cinnamon tree Broader terms laurel Parts Cinnamomum Part of cinnamon WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.