When you have a nasty cold and you’re very congested, food can taste unappealingly bland. That means dull, flavorless, or just plain “blah.”
Bland comes to us from the Latin word blandus, meaning “mild, smooth, flattering, alluring.” Funny, because today you wouldn't say there's anything "alluring" about something bland. People still use bland to mean pleasant and tranquil, but it more often has a negative connotation. Use it to describe plain old oatmeal before you’ve added brown sugar and berries to it, or to depict the forgettable, uninteresting personality of the lunch lady who served it to you.