Synonyms and related words :
dead, dilute, diluted, distasteful, fade, flat, gruelly, ill-flavored, inane, indifferent, insipid, jejune, mild, milk-and-water, pappy, pulpy, sapless, savorless, spiceless, stale, tasteless, thin, unappetizing, unflavored, unsavory, vapid, washy, watered, watered-down, watery, weak, wishy-washy