Source of cinnamon spice (4)
I believe the answer is:
bark
'source of cinnamon spice' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for bark that I've seen before include "graze" , "Sound made by a dog" , "Sound from animal < having part of tree" , "Three-master - tree covering - wolf cry" , "Shout gruffly; part of tree" .)