| strenuous(adjective, dull, difficult, awkward, boring) |
| uninteresting(adjective, dull, boring, tedious, irritating) |
| monotonous(adjective, dull, boring, tedious, irritating) |
| onerous(adjective, dull, difficult, awkward, boring) |
| toilsome(adjective, hard, tough, severe, rough) |
| annoying(verb, adjective, dull, boring, tedious) |
| enfeebling(adjective, verb) |
| gruelling |
| sapping(verb, adjective, trying, exhausting, tiring) |
| soporific |
| stiff(adjective, hard, difficult, demanding, protracted) |
| taxing(adjective, hard, tough, severe, difficult) |
| trying(adjective, dull, boring, tired, tedious) |
| back-breaking |
| jading(adjective, dull, boring, tedious, irritating) |
| severe(adjective, hard, tough, rough, difficult) |
| weary(adjective, fatigue) |
| dispiriting |
| dulling(verb, boring) |
| flat(adjective, dull, boring, tedious, dreary) |