means Relating to a skeleton, or reduced to the bare bones — describing something extremely thin, or a structure stripped down to its essential framework.

from From the Greek 'skeletos,' meaning 'dried up' or 'withered' — the word for a mummy or dried body, built from 'skellein,' to dry out. The skeleton, then, is literally 'the dried thing': what remains when everything soft and living has been parched away. English took it up by the 17th century, and 'skeletal' followed as the adjective for anything sharing that bare, desiccated quality.