Reverse Dictionary: REGRET

ADJECTIVES
1605 ► having or feeling compunction; pricking to the conscience; causing regret or misgiving; remorseful, repentant → COMPUNCTIOUS 
1887 ► regretful, lamenting → ICHABODIAN 
1905 ► sad, sorrowful, regretful → OFF → Eng. dial. (Bk.)
1930 ► regrettable, bad → POPEYED → sl.

INTERJECTIONS
1528 ► an exclamation of surprise, regret, or sorrow; ah! oh! alas! → OCH! → Sc. & Irish
1694 ► a mild register of anxiety, irritation, regret, etc. → DEAR! 
1694 ► a mild register of anxiety, irritation, regret, etc. → DEAR OH DEAR! → UK
1694 ► a mild register of anxiety, irritation, regret, etc. → OH DEAR! → UK
L17 ► expressing surprise, regret, or grief → LACKADAY! → arch.
1765 ► an exclamation of sorrow or regret → OH-ANEE! → Sc.
1785 ► an exclamation of sorrow or regret → OHON! → Sc.
1787 ► an exclamation of sorrow or regret → OCHON! → Sc.
1790 ► an exclamation of sorrow or regret → OCH-AND-ANEE! → Ireland
1838 ► an exclamation of sorrow or regret → OCH-HEY! → Sc.
M18 ► expressing surprise, regret, or grief → LACKADAISY! 
1865 ► an exclamation of regret or surprise → DEARY ME TO-DAY! → Eng. dial.  
1865 ► an exclamation of sorrow or regret → OCH HON! → Sc.
1865 ► an exclamation of sorrow or regret → OCH HON A-CHREE! → Sc.
1865 ► an exclamation of sorrow or regret → OCHONE! → OCH-ON-EE! → Sc.
1892 ► an exclamation of sorrow or regret → OCHANEE! → Sc.
1898 ► an exclamation of regret or pity → AY-DI-ME! → Sc. (Bk.)
1899 ► an exclamation of sorrow or regret → OCH-AN-HEIGH-HO! → Eng. dial.
1980 ► an exclamation of regret; that’s really terrible! oh no! I’m so sorry! → MULTIPLE SADNESS! → US college sl.
1980 ► a mild exclamation of surprise, regret, annoyance, etc. → SHACKS! → US college sl.
1994 ► expressing frustration, regret, or annoyance; damn! → ARSE! → UK sl.

NOUNS
1200 ► a matter for sorrow or regret; an occasion of sorrow or regret → RUTH → obs.
1385 ► a matter for regret, a misfortune → DAMAGE → obs.
1390 ► a phrase (if I had known), expressing regret for something done in ignorance of circumstances now known; hence, a vain regret, or the heedlessness or loss of opportunity which leads to it → HAD-I-WIST → obs.
1596 ► sorrowfulness; regretfulness → RUTHFULNESS → rare
1636 ► something to be regretted → CRIME → colloq.
1815 ► a source of regret, sorrow, or annoyance; a trouble; a cause or state of vexation, annoyance, or worry → VEX → Sc.
1825 ► a cause of regret → EELIST → Sc. obs.
1862 ► hesitation, doubt, regret → HANKER → Eng. dial.
1920 ► shame or regret at certain word or act → ATIFER → Sc.
1966 ► a feeling of regret experienced after making a purchase, typically one regarded as unnecessary or too expensive → BUYER’S REMORSE 

VERBS
1000 ► to cause one grief or regret → OFTHINK  → obs.
1659 ► to regret deeply some undertaking, and repent of it; to be in a state of lamentation; to fail; to suffer defeat → RETURN BY WEEPING CROSS 
1682 ► to regret, to repent, to grudge → BETHINK → obs.
1843 ► to cry; to experience unexpected failure, defeat, or regret → LAUGH ON THE OTHER SIDE OF ONE’S MOUTH → Amer. dial.
1847 ► to feel remorse; to regret something → WHIP THE CAT → Aust. sl.
1899 ► to cry; to experience unexpected failure, defeat, or regret → LAUGH ON THE WRONG SIDE OF ONE’S MOUTH → Amer. dial.
1904 ► to regret something; to repent → SIT OVER ONE’S SADS → N. Ireland (Bk.)
1911 ► to regret; to ill-wish → BEGRUDGE → Sc. (Bk.)
1912 ► to cry; to experience unexpected failure, defeat, or regret → LAUGH OUT OF THE OTHER CORNER OF ONE’S MOUTH → Amer. dial.
1946 ► to cry; to experience unexpected failure, defeat, or regret → LAUGH ON THE OTHER SIDE OF ONE’S FACE → Amer. dial.
1973 ► to suffer protracted humiliation, obloquy, regret, etc. → TWIST SLOWLY IN THE WIND → US sl.