Noun:

1. the quality of being enduring and free from change or variation;

   "early mariners relied on the constancy of the trade winds"
   

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

3. faithfulness and dependability in personal attachments (especially sexual fidelity)

stabilityn.稳定性；居于修道院

virtuen.美德；德行；优点；贞操

continuancen.继续；停留；持续；[律]延期审理

faithfulnessn.忠诚；诚实

loyaltyn.忠诚；忠心；忠贞

fidelityn.忠实；忠诚；准确性；保真度

dependabilityn.可依赖性；可靠性

reliabilityn.可靠性

devotionn.虔诚；献身；奉献；热爱

steadinessn.稳健；坚定；不变

firmnessn.坚固；坚牢；坚定

consistencyn.连贯；一致性；强度；硬度；浓稠度

steadfastnesssteadfast的名词形式

endurancen.忍耐；忍耐力；耐性

single-mindednessn.忠贞；专心

perceptual constancy知觉常性

inconstancyn.易变；不定性；不忠实

1. Constancy in love is a good thing.
   爱情能持之以恒才是好事。
2. The secret of success is constancy of purpose .
   成功的秘诀是目标的坚定性。
3. He admired her courage and constancy.
   他钦佩她的勇气和忠贞。
4. Never doubt the constancy of my love for you.
   绝对不要怀疑我对你爱的忠诚。