Definitions: (1) capable of enduring hardship; robust; (2) having a sturdy constitution; strongly built

• No member of a crew is praised for the rugged individuality of his rowing. — Ralph Waldo Emerson (1803-1882) American poet
• Mankind progresses not smoothly, as by a sliding carpet ascent, but by rugged steps broken by gaps. He halts long on one stage before taking the next. Often he remains stationary, unable to form resolution to step forward – sometimes even has turned round and retrograded. — Sabine Baring-Gould (1834–1924) English hagiographer & novelist