1 : to draw a line under : underscore. 2 : to draw or depict inadequately. 3 : to overlay or line (a roof or ceiling) with thin boards or lath and plaster. 4 : to draw from (an account) less than the amount credited.

What do you mean by anatomical?

: of or relating to anatomy or the body structure of organisms anatomical studies/structures/mechanisms The mollusks are divided according to common anatomical traits into seven classes …— Carol M.

What is an Underdrawn ceiling?

1) To underdraw a ceiling or roof is to cover the underside of exposed beams and joists, either with boards or with lath and plaster.