(1):

(n.) The quality or state of being tenuous; thinness, applied to a broad substance; slenderness, applied to anything that is long; as, the tenuity of a leaf; the tenuity of a hair.

(2):

(n.) Rarily; rareness; thinness, as of a fluid; as, the tenuity of the air; the tenuity of the blood.

(3):

(n.) Poverty; indigence.

(4):

(n.) Refinement; delicacy.