Entry 1 sense Webster, 1913 Fibroma /(fī̇*brō"mȧ)/ · Fi·bro·ma · IPA /faɪˈbɹoʊmə/ 01 n. A tumor consisting mainly of fibrous tissue, or of same modification of such tissue. 1. A tumor consisting mainly of fibrous tissue, or of same modification of such tissue.(Med.)