Word Study
regrettable
OXFORD DICTIONARY
regrettable, adj. (of events or conduct) undesirable, unwelcome; deserving censure.
Derivative
regrettably adv.
THESAURUS
regrettable
abominable, affecting, afflictive, arrant, atrocious, awful, base, beastly, beneath contempt, bitter, blameworthy, bleak, brutal, calamitous, cheerless, comfortless, contemptible, deplorable, depressing, depressive, despicable, detestable, dire, discomforting, disgusting, dismal, dismaying, distressful, distressing, dolorific, dolorogenic, dolorous, dreadful, dreary, egregious, enormous, execrable, fetid, filthy, flagrant, foul, fulsome, grievous, gross, hateful, heartbreaking, heinous, horrible, horrid, infamous, joyless, lamentable, loathsome, lousy, monstrous, mournful, moving, nasty, nefarious, noisome, notorious, obnoxious, odious, offensive, outrageous, painful, pathetic, piteous, pitiable, pitiful, poignant, rank, reprehensible, repulsive, rotten, rough, rueful, sad, saddening, scandalous, schlock, scurvy, shabby, shameful, shaming, sharp, shocking, shoddy, sordid, sore, sorrowful, squalid, terrible, too bad, touching, tough, unclean, uncomfortable, unfortunate, unhappy, unlucky, upsetting, vile, villainous, woebegone, woeful, worst, worthless, wretched, wrongROGET THESAURUS
regrettable
Regret
N regret, repining, homesickness, nostalgia, mal du pays, maladie, lamentation, penitence, bitterness, heartburning, recrimination (accusation), laudator temporis acti, regretting, regretful, homesick, regretted, much to be regretted, regrettable, lamentable, regrettably, unfortunately, most unfortunately, Int, alas!, what a pity!, hang it!, 'tis pity, 'tis too true, sigh'd and look'd and sigh'd again, I'm sorry.For further exploring for "regrettable" in Webster Dictionary Online