constancy

noun

1. (uncountable, usually)The quality of being constant; steadiness or faithfulness in action, affections, purpose, etc.

   “A little Water cleares vs of this deed. How eaſie is it then? your Conſtancie Hath left you vnattended.”

   “Punctuality is a species of Constancy, a very unfashionable quality in a Lady.”

   “And, I do not know that I should be fond of preaching often; now and then, perhaps, once or twice in the spring, after being anxiously expected for half a dozen Sundays together; but not for a constancy; it would not do for a constancy.”

   “Constancy of character is what is chiefly valued and sought for by naturalists.”

   “The overall retention rate of 68 per cent indicates a robust constancy of the linguistic features investigated.”

2. (countable, usually)An unchanging quality or characteristic of a person or thing.

   “[…] yonger ſpirits, […] whoſe conſtancies Expire before their faſhions: […]”