| clement(adjective, calm, weak, smooth, soft) |
| cold |
| cool(adjective, calm, weak, smooth, pleasant) |
| dainty(adjective, calm, weak, smooth, pleasant) |
| delicate(adjective, calm, weak, smooth, pleasant) |
| demanding(adjective, dull, boring, tired, tedious) |
| demulcent(adjective, calm, weak, smooth, soft) |
| diddly(adjective, bad, simple, flat, clean) |
| difficult(adjective, dull, boring, tired, tedious) |
| dim(adjective, dull, flat, boring, lifeless) |
| dismal |
| drag(adjective, dull, boring, disagreeable, tedious) |
| dragger(disagreeable, uninspired, uninspiring, workaday, weariful) |
| dragging(adjective, dull, boring, tired, tedious) |
| drearisome |
| droning(adjective, dull, flat, boring, tedious) |
| drudging(adjective, dull, boring, tedious, dreary) |
| dryasdust |
| dull as dishwater(expression, adjective, idiom, dull, boring) |
| effete |