Tree bark is a common feature on the trunk and branches of trees, and it serves to protect and support the tree. Many people may have come across this feature, but there are several other synonyms for tree bark. Some of these include the outer covering, the exterior layer, the rind, the skin, the covering, the sheath, and the casing, among others. Although all these terms point to the same feature, they showcase how vast the English language is and how you can use a variety of synonyms to achieve diversity in your writing.