#1 ruggedness n. [huskiness, toughness] the property of being big and strong. wn
#2 ruggedness n. the quality of being topologically uneven; "the ruggedness of the mountains". wn
#3 ruggedness n. [hardness] the quality of being difficult to do; "he assigned a series of problems of increasing hardness"; "the ruggedness of his exams caused half the class to fail". wn
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