tenuity

(noun) relatively small dimension through an object as opposed to its length or width. Synonyms: thinness, slenderness. Examples: "The tenuity of a hair." "The thinness of a rope."

(noun) a rarified quality. Synonyms: rarity, low density. Example: "The tenuity of the upper atmosphere."

(noun) the quality of lacking intensity or substance. Synonyms: feebleness. Example: "A shrill yet sweet tenuity of voice"- nathaniel hawthorne."