Antonyms of adj tasteful

2 senses of tasteful

Sense 1
tasteful (vs. tasteless) -- (having or showing or conforming to good taste)

tasteless (vs. tasteful) -- (lacking aesthetic or social taste)
        => barbaric -- (unrestrained and crudely rich; "barbaric use of color or ornament")
        => brassy, cheap, flash, flashy, garish, gaudy, gimcrack, loud, meretricious, tacky, tatty, tawdry, trashy -- (tastelessly showy; "a flash car"; "a flashy ring"; "garish colors"; "a gaudy costume"; "loud sport shirts"; "a meretricious yet stylish book"; "tawdry ornaments")
        => Brummagem -- (cheap and showy; "a cheap Brummagem imitation")
        => camp, campy -- (providing sophisticated amusement by virtue of having artificially (and vulgarly) mannered or banal or sentimental qualities; "they played up the silliness of their roles for camp effect"; "campy Hollywood musicals of the 1940's")
        => indelicate, off-color, off-colour -- (in violation of good taste even verging on the indecent; "an indelicate remark"; "an off-color joke")
        => ostentatious, pretentious -- ((of a display) tawdry or vulgar)

Sense 2
neat, refined, tasteful -- (free from what is tawdry or unbecoming; "a neat style"; "a neat set of rules"; "she hated to have her neat plans upset")

INDIRECT (VIA elegant) -> inelegant -- (lacking in refinement or grace or good taste)

Similarity of adj tasteful

2 senses of tasteful

Sense 1
tasteful (vs. tasteless) -- (having or showing or conforming to good taste)
       => aesthetic, esthetic, artistic -- (aesthetically pleasing; "an artistic flower arrangement")
       => understated, unostentatious, unpretentious -- (exhibiting restrained good taste; "the room is pleasant and understated")
          Also See-> elegant#1; unpretentious#1

Sense 2
neat, refined, tasteful -- (free from what is tawdry or unbecoming; "a neat style"; "a neat set of rules"; "she hated to have her neat plans upset")
       => elegant (vs. inelegant) -- (refined and tasteful in appearance or behavior or style; "elegant handwriting"; "an elegant dark suit"; "she was elegant to her fingertips"; "small churches with elegant white spires"; "an elegant mathematical solution--simple and precise and lucid")