ruggedness

Concise Oxford English Dictionary © 2008 Oxford University Press:
rugged /ˈrʌgɪd/

▶adjective

• 1 having a rocky and uneven surface.

• 2 having or requiring toughness and determination.

  ■ (of a man) having attractively masculine, rough-hewn features.

– derivatives
ruggedly adverb,
ruggedness noun.

– origin ME (in the sense ‘shaggy’): prob. of Scand. origin; cf. rug.