Definitions for "Barrier Option"
A path dependent option whose pay-off pattern depends not only on the path that the price of the underlying asset follows during the life of the option, but also on whether or not the underlying assets breaks a predetermined price level at any time during the life of the option.
A type of option where the payout depends on whether or not the underlying asset reaches a predetermined price.
An Option which will either become effective or cease to exist if the underlying instrument trades at some predetermined price prior to expiration. Common names for barrier Options include "down-and-out" and "up-and-over" Options, and "knock-out" and "kick-in" Options.