fibromatosis gingi´vae (gingival fibromatosis) a noninflammatory fibrous hyperplasia of the gingivae and palate, manifested as a dense, smooth, or nodular overgrowth of the tissues.It is usually inherited as an autosomal dominant trait, but some cases are idiopathic and others are produced by drugs.ibromatosis. 1. the presence of multiple fibromas. 2. the formation of a fibrous, tumor-like nodule arising from the deep fascia, with a tendency to local recurrence. fibromatosis gingivae, gingival fibromatosis. see epulis.