Webster’s Revised Unabridged Dictionary · 1913
Staidness
Staid′ness, n. The quality or state of being staid; seriousness; steadiness; sedateness; regularity; — the opposite of wildness, or levity.
If sometimes he appears too gray, yet a secret gracefulness of youth accompanies his writings, though the staidness and sobriety of age wanting. Dryden.
Syn. — Sobriety; gravity; steadiness; regularity; constancy; firmness; stability; sedateness.