adj. insípido, desaborido, desabrido, desazonado, insulso, sin gusto, sin sabor, soso; de mal gusto

The following video provides you with the correct English pronunciation of the word "tasteless", to help you become a better English speaker.

simple | simplón | insaboro | insípido | desabrido | sin gusto | insulso | pasmado | de mal gusto

(adj.) = insípido, sin sabor, desabrido.
Ex: Carbon monoxide is a colourless, odourless, and tasteless gas and is the product of the incomplete combustion of carbon-containing compounds.

(adj.) = de mal gusto, burdo, chabacano, grosero, vulgar, ordinario, zafio, soez.
Ex: Of the hundreds of figurines currently on the market, here are the most bizarrely tasteless.