According to the Gottman Institiute, flooding is "a sensation of feeling psychologically and physically overwhelmed during conflict, making it virtually impossible to have a prodcutive, problem-solving discussion."
Brene Brown Atlas of the Heart p. 197
We each have a sort of built in meter that measures how much negativity accumulates during such interactions. When the level gets too high for you, the needle starts going haywire and flooding begins.
Brene Brown Atlas of the Heart p. 197
The Heart is Open