fibrosis Syllabification: (fi·bro·sis)Pronunciation: /fīˈbrōsəs/Definition of fibrosis noun Medicine the thickening and scarring of connective tissue, usually as a result of injury. Derivatives fibroticPronunciation: /fīˈbrätik/ adjective Origin: late 19th century: from Latin fibra (see fiber) + -osisfibrosis in other Oxford dictionaries Definition of fibrosis in the British & World English dictionary