dissociation constant: the equilibrium constant for a reversible dissociation
equilibrium constant: (chemistry) the ratio of concentrations when equilibrium is reached in a reversible reaction (when the rate of the forward reaction equals the rate of the reverse reaction)
bullbrier: a very prickly woody vine of the eastern United States growing in tangled masses having tough round stems with shiny leathery leaves and small greenish flowers followed by clusters of inedible shiny black berries