Noun
underactivity (uncountable)
insufficient activity
After delivery, the gland becomes inflamed and the condition initially presents with overactivity of the gland followed by underactivity. Source: Internet
Additionally, speech production in people who stutter yields underactivity in cortical motor and premotor areas. Source: Internet
In other species, the changes may not be triggered because of underactivity of the hypothalamus-pituitary-thyroid mechanism which may occur when conditions in the terrestrial environment are too inhospitable. Source: Internet