1) Dreariest 2) Least exciting 3) Least interesting 4) Least lustrous 5) Most dreary 1) Tamest 
dull, duller, dullest, dullness, dullish 1. Intellectually weak or obtuse; stupid; mentally very slow. 2. Lacking responsiveness or alertness; insensitive. 3. Dispirited; depressed. 4. Not brisk or rapid; sluggish. 5. Not having a sharp edge or point; blunt; such as, a dull knife. 6. Not intensely or keenly felt; for example, a dull ache. 7. ...