The opposite of "be dazzling" is to be unremarkable or unimpressive. Some antonyms that can be used for this word include dull, uninteresting, plain, modest, lackluster, and unexciting. "Dull" refers to something lacking in brightness or interest, while "uninteresting" suggests a lack of appeal or compelling features. "Plain" describes something that lacks decoration or adornment, while "modest" suggests a lack of pretension. "Lackluster" refers to something that is lacking in vitality or energy, while "unexciting" suggests a lack of excitement or interest. These antonyms highlight the contrast between something that is dazzling and something that is unremarkable or uninspiring.