Definition of osiers:
(n) :
(loosely) Any kind of willow.
(n) :
(countable, uncountable) Long, pliable twigs of this plant, or of other similar plants.
(n) :
A willow, of species Salix viminalis, growing in wet places in Europe and Asia, and introduced into North America, considered the best willow for wickerwork.
(n) :
A surname from French.