An obstacle to meeting a goal.
Control, especially of a flow or process (as a valve controls the flow of water by blocking it).
Lack of control (as a blocked water pipe causes a loss of control that results in flooding).
A stoppage or holdup in a process (such as “writer’s block”).
A way to fix a leak (such as of information) or stop a loss (such as of wasted effort).
See Breakwater, Divider, Interrupting, Interfering, Sabotaged, Being, Closing, Problem, Denying, Tight, Closed