horsebrier \horsebrier\ n.
a very prickly woody vine ({Smilax rotundifolia}) of eastern
U. S. growing in tangled masses having tough round stems with
shiny leathery leaves and small greenish flowers followed by
clusters of inedible shiny black berries.
Syn: bullbrier, greenbrier, catbrier, brier, briar, {Smilax
rotundifolia}.
[WordNet 1.5]