From Longman Dictionary of Contemporary Englishosiero‧si‧er /ˈəʊziə, ˈəʊʒə $ ˈoʊziər, ˈoʊʒər/ noun [countable] HBPa willow tree whose branches are used for making baskets
Examples from the Corpus
osier• Big osier ones, flat, that you could crook over your arm or set on the ground.• From the hides, shimmering water meadows, fingered spits islands, orange-tinged osiers and countless bobbing birds lay exposed to view.• Two osier baskets each: one for red tomatoes and one for green.