Plain English Meaning
Getting frustrated or snappy more easily than usual — small things start to bother you when they normally wouldn't. In aviation, this is treated as a warning sign that someone is tired, not just having a bad day.
Full Definition
A behavioural symptom of fatigue in which a person becomes unusually short-tempered, easily annoyed, or quick to react negatively to minor problems, instructors, students, or situations that would not normally provoke such a response.
Context Anchor
Seen in aviation human factors discussions, especially when identifying signs of fatigue before or during flight.
Derivation
From the Latin 'irritare', meaning 'to provoke' or 'to excite'. The word describes how easily a person can be 'provoked' into a negative reaction — useful in aviation because fatigue lowers the threshold at which provocation occurs.
Why Pilots Care
Fatigue-induced irritability can degrade crew , increase the chance of conflict, and to in or .