Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
ruggedness is a noun meaning "the property of being big and strong". It carries 3 recorded senses.
the quality of being topologically uneven
“the ruggedness of the mountains”
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”
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for ruggedness come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.