постоянство означава в английски

consistency [consistencies]▼(reliability or uniformity; the quality of being consistent)
noun
[UK: kən.ˈsɪ.stən.si] [US: kən.ˈsɪ.stən.si]

constancy [constancies]▼(The quality of being constant)
noun
[UK: ˈkɒn.stən.si] [US: ˈkɑːn.stən.si]

permanence▼(the state of being permanent)
noun
[UK: ˈpɜː.mə.nəns] [US: ˈpɝː.mə.nəns]

perseverance▼(persistent determination to adhere to a course of action; insistence)
noun
[UK: ˌpɜː.sɪ.ˈvɪə.rəns] [US: ˌpər.sə.ˈvɪ.rəns]

persistence▼(property of being persistent)
noun
[UK: pə.ˈsɪ.stəns] [US: pər.ˈsɪ.stəns]

impermanence▼(lack of permanence)
noun
[UK: ɪm.ˈpɜː.mə.nəns] [US: ɪm.ˈpɝː.mə.nəns]

fickleness▼(quality of being fickle)
noun
[UK: ˈfɪkl.nəs] [US: ˈfɪk.əl.nəs]