1. The outer part of the bark of a woody plant that is external to the last formed periderm.
2. The outer bark consisting of a periderm and tissues isolated by it.

In woody plants, tissues external to the vascular cambium (the growth layer of the vascular cylinder); the term bark is also employed more popularly to refer to all tissues outside the wood. The inner soft bark, or bast, is produced by the vascular cambium; it consists of secondary phloem tissue whose innermost layer conveys food from the leaves to the rest of the plant.