constancy, stability (noun)
the quality of being enduring and free from change or variation
"early mariners relied on the constancy of the trade winds"
constancy, perceptual constancy (noun)
(psychology) the tendency for perceived objects to give rise to very similar perceptual experiences in spite of wide variations in the conditions of observation
faithfulness and dependability in personal attachments (especially sexual fidelity)
firmness, soundness (noun)
the muscle tone of healthy tissue
"his muscular firmness"
resoluteness, firmness, firmness of purpose, resolve, resolution (noun)
the trait of being resolute
"his resoluteness carried him through the battle"; "it was his unshakeable resolution to finish the work"
the property of being unyielding to the touch
steadiness, firmness (noun)
the quality of being steady or securely and immovably fixed in place