Anything that discourages.
The act of discouraging.
The loss of confidence or enthusiasm.
A thing that frustrates.
The feeling of annoyance at impassibility from resistance.
The state of contract that allows a party to back away from its contractual obligations due to (unforeseen) radical changes to the nature of the thing a party has been obligated to.
The act of frustrating, or the state, or an instance of being frustrated.
Anger not directed at anything or anyone in particular.