遺憾

Adjective

 * 1) regrettable; pitiable
 * 2)  regrettable; unfortunate indicating discontent, protest or apology

Noun

 * 1) regret; eternal regret

Verb

 * 1) to regret; to pity; to be sorry about

Etymology
遺 (い, i: “leave”, "remain") + 憾 (かん, kan: “regret")

Adjective

 * 1) feeling a regret that come from a failure of one's intention
 * 2) feeling a regret with pity, sadness, disappointment, and shame because the result is not one's intention

Noun

 * 1) a regret that come from a failure of one's intention
 * 2) a regret with pity, sadness, disappointment, and shame because the result is not one's intention