Definition of osier

• n. - A kind of willow (Salix viminalis) growing in wet places in Europe and Asia, and introduced into North America. It is considered the best of the willows for basket work. The name is sometimes given to any kind of willow.
• n. - One of the long, pliable twigs of this plant, or of other similar plants.
• a. - Made of osiers; composed of, or containing, osiers.