| fussy(adjective, difficult, thorough, meticulous, painstaking) |
| hearty(adjective, strong, tough, intense, energetic) |
| intensive |
| mean(adjective, strong, hard, severe, rough) |
| painful(adjective, hard, tough, severe, difficult) |
| pertinacious |
| rigorous(adjective, hard, tough, severe, rough) |
| robust(adjective, strong, tough, intense, energetic) |
| serious(adjective, hard, severe, rough, difficult) |
| sprightly(adjective, action, strong, moving, lively) |
| sticky(adjective, tough, rough, difficult, heavy) |
| straining |
| ticklish(adjective, difficult) |
| vigourous |
| wearing(adjective, dull, difficult, awkward, boring) |
| zestful(adjective, energetic, vigorous, lusty) |
| ambitious(adjective, tough, severe, ability, painful) |
| bold(adjective, tough, smart, energetic, active) |
| breathless |
| combative(adjective, antagonistic, aggressive, argumentative) |