the quality of being enduring and free from change or variation; "early mariners relied on the constancy of the trade winds"耐久性があり、変化や変動のない性質操守
例:early mariners relied on the constancy of the trade winds 昔の船員は、貿易風の不変性に頼った
(psychology) the tendency for perceived objects to give rise to very similar perceptual experiences in spite of wide variations in the conditions of observation観測の状態が多様であるにもかかわらず、認識された物体が、とてもよく似た知覚体験をもたらすという傾向恒常性