Noun tautness has 2 senses

• tautness(n = noun.state) tenseness, tension, tensity - the physical condition of being stretched or strained; "it places great tension on the leg muscles"; "he could feel the tenseness of her body"
is a kind of condition, status
has particulars: tone, tonicity, tonus
Derived form adjective taut₂

• tautness(n = noun.attribute) tightness - lack of movement or room for movement; Array
is a kind of immovability, immovableness
Derived form adjective taut₁