Tonus and Tautness

Tonus noun - The elastic tension of living muscles, arteries, etc. that facilitate response to stimuli.

Tautness and tonus are semantically related. In some cases you can use "Tautness" instead a noun "Tonus".

Tautness noun - The physical condition of being stretched or strained.

Tonus and tautness are semantically related. Sometimes you can replace term "Tonus" with "Tautness", this nouns are similar.