Irrationality is an attitude of consciousness aimed at direct perception of what is happening. This is the perception of what is happening in the live impression mode, directly, with wide open eyes and soul, without doubt and critical evaluation.
When this happens one-time, perhaps by accident, they speak more about a living impression. If this is not a one-time event, but an attitude of consciousness or, moreover, a personal habit, then this is already irrationality as a personal feature and trait.
The opposite of irrationality is rationality and rationalism.