A suffix, properly added only to words derived from Greek roots, noting a tumor or neoplasm.
- A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.

Usage examples:

This word " oma is added to the stem of the word ordinarily used to designate the kind of tissue of which the tumor is composed.
- Special Report on Diseases of Cattle by U.S. Department of Agriculture J.R. Mohler
He found her in a town called Oma two leagues from Cuzco, asked for her from her guardians, and, with their consent, brought her to Cuzco.
- History of the Incas by Pedro Sarmiento de Gamboa