Torpor is a state of mental and physical inactivity. "After a huge Thanksgiving meal, my family members fall into a torpor; no one can even pick up the TV remote."
Torpor can be used in everyday speech, but it's also a scientific term for a state of deep sleep that allows animals to conserve energy. Certain species of bats, birds, and frogs rely on torpor for survival during tough times. While humans don't technically belong to this group of animals, they certainly appear to, especially after a large meal and on most Monday mornings.