Antonyms of delectable:
undesirable, tasteless, unwanted, abominable, ghastly, god-awful, hellish, horrid, miserable, wretched, bilious, disgusting, distasteful, obnoxious, offensive, repellent, repugnant, repulsive, revulsive, unsavory, vile, yucky, abhorrent, detestable, hateful, odious, boring, commonplace, dull, flat, insipid, irksome, stale, tedious, displeasing, dissatisfying, depressing, disheartening, dismal, dreary, gloomy, heartbreaking, heartrending, joyless, lachrymose, sad, unhappy, deplorable, doleful, dolorous, lamentable, lugubrious, mournful, regrettable, sorrowful, tragic, aggravating, annoying, exasperating, irritating, peeving, perturbing, vexing, forbidding, hostile, intimidating, angering, enraging, incensing, inflaming, infuriating, maddening, outraging, rankling, riling, distressing, disturbing, upsetting, disagreeable, pleasureless, unpalatable, unpleasant, unwelcome, banal, noisome, smelly, stinky, noxious, unwholesome, awful, foul, nauseating, sickening, flavorless, unappetizing.
Examples of usage:
  1. Sweet, kind, delectable vengeance, indeed!
    "The Outlaw of Torn", Edgar Rice Burroughs.
  2. It was annoying to think that Westby had been standing by and finding perhaps in his nervousness a delectable subject for mockery and derision.
    "The Jester of St. Timothy's", Arthur Stanwood Pier.
  3. The whole fraternity eat together; and such a delectable way of life has never been seen on earth since the days of the early Christians.
    "The Life and Genius of Nathaniel Hawthorne", Frank Preston Stearns.