tasteless
UK: ˈteɪstləs | US: ˈteɪstləs
adj. lacking flavor; bland or insipid
adj. showing poor judgment or lacking refinement; vulgar
The word "tasteless" combines "taste," derived from Old French taster (to touch, try, or taste) and ultimately Latin taxare (to evaluate), with the suffix "-less," from Old English -lēas (without). Originally, "taste" referred to the sense of flavor, and "-less" negates it, creating a literal meaning of "without flavor." Over time, it gained a figurative sense ("lacking refinement") by analogy—just as bland food lacks stimulation, tasteless behavior lacks social grace.
The soup was tasteless, as if no spices had been added.
His tasteless jokes made everyone uncomfortable at the party.
The decor was criticized for being cheap and tasteless.
Without salt, the dish would be completely tasteless.
She wore a tasteless outfit that clashed with the formal event.