constancy

名词 constancy:

1. the quality of being enduring and free from change or variation
   同义词：stability
2. (psychology) the tendency for perceived objects to give rise to very similar perceptual experiences in spite of wide variations in the conditions of observation
   同义词：perceptual constancy
3. faithfulness and dependability in personal attachments (especially sexual fidelity)

1. He is a husband of constancy.
   他是个忠贞不渝的丈夫。
2. He has constancy of purpose.
   他有坚定不移的目标。

con.stan.cy

n.（名词）
Steadfastness, as in purpose or affection; faithfulness.
坚定：（目标或感情上的）坚定不移；忠诚
The condition or quality of being constant; changelessness.
始终如一：始终如一的情形或性质；持久不变