| 十年一日 | [じゅうねんいちじつ;じゅうねんいちにち, juunen'ichijitsu ; juunen'ichinichi] (n) without intermission for ten (long) years; with constancy of purpose for ten (long) years; in the same old rut for years on end |
| 千年一日 | [せんねんいちじつ, sennen'ichijitsu] (n) without intermission for many years; with constancy of purpose for many years; in the same old rut for years on end |
| 恒心 | [こうしん, koushin] (n) steadiness; constancy |
| 恒性 | [こうせい, kousei] (n) constancy |
| 不定 | [ふじょう(P);ふてい, fujou (P); futei] (adj-na,n,adj-no) uncertainty; insecurity; inconstancy; indefinite; undecided; (P) |
| 不実 | [ふじつ, fujitsu] (adj-na,n,adj-no) perfidiousness; faithlessness; inconstancy; insincerity; falsehood |
| 不断 | [ふだん, fudan] (n-t,adj-na,adj-no) (1) (See 普段) constancy; persistency; continuity; (adj-na) (2) indecisive; (P) |
| 変心 | [へんしん, henshin] (n,vs) change of mind; inconstancy; apostasy |
| 心変わり | [こころがわり, kokorogawari] (n) change one's mind; inconstancy; faithlessness |
| 志操堅固 | [しそうけんご, shisoukengo] (n,adj-na) being faithful to one's principles; being of firm purpose and deep commitment; constancy; true blue |
| 性悪 | [しょうわる;せいあく, shouwaru ; seiaku] (adj-na,n) ill-natured; inconstancy |
| 恒常 | [こうじょう, koujou] (n) constancy; (P) |
| 恒常性 | [こうじょうせい, koujousei] (n) constancy; homeostasis; homoeostasis |
| 松柏 | [しょうはく;まつかえ, shouhaku ; matsukae] (n) (1) evergreen tree; conifer; coniferous tree; (2) pine and cypress; (3) duty; constancy; faithfulness |
| 浮気(P);うわ気 | [うわき, uwaki] (n,adj-na,vs) (1) (sens) extramarital sex; affair; fooling around; (2) infidelity; wantonness; unfaithfulness; inconstancy; fickleness; caprice; (P) |
| 節操 | [せっそう, sessou] (n) (1) constancy; integrity; honor; honour; (2) chastity; fidelity; (P) |