| adjective | having rugged physical strength; inured to fatigue or hardships “hardy explorers of northern Canada” |
| adjective | not making concessions “took an uncompromising stance in the peace talks” |
| adjective | substantially made or constructed “sturdy steel shelves” |
| hardiness | noun | the property of being strong and healthy in constitution |
| stoutness | noun | the property of being strong and resolute |
| sturdiness | noun | the state of being vigorous and robust |
| inflexibility | noun | the quality of being rigid and rigorously severe |