Medical term for loss of motor function. Often used in compounds such as 半身不随 (hemiplegia).
祖父は脳卒中で半身不随になった。
My grandfather became paralyzed on one side due to a stroke.
hemiplegia; paralysis on one side of the body
total paralysis
From 不 (not) + 随 (follow, obey), literally 'not following one's will', referring to loss of voluntary movement.