Debility is weakness caused by an illness, injury, or aging. Very elderly people often need extra care because of debility.
Debility is similar to disability, although the first term tends to describe a slower process of slowing and weakening, either physically or mentally. It comes from the Latin debilitatem, "a weakening," and its roots, the prefix de-, "from or away," and -bilis, "strength." A lack of proper nutrition over a long period can cause debility, and the very act of living to be 120 is sure to result in debility as well.