Catatonic
Etymology
From Greek kata-, "down," and tonos, "tension" or "tone." The literal sense is tension pulled down — a body locked and unresponsive. The psychiatrist Karl Kahlbaum introduced "catatonia" in 1874 to describe this state. Medically it can involve either frozen stillness or agitation, but everyday use fixes on the stunned, motionless image.
adjective · /kat-uh-TON-ik/
In a state of near-total immobility and unresponsiveness, sometimes with a rigid or held posture.
What it names
A precise word for a striking clinical state, often borrowed loosely for the frozen blankness of shock or exhaustion.
Example
After the news, she sat almost catatonic, staring at the wall.
Related idea
Torpor is sluggish, drowsy inactivity; catatonic describes a far more complete, arrested stillness.