-omacomb. form

Etymology: < -oma (in words such as carcinoma n. and sarcoma n.) or its etymon Greek -ωμα ( < ω- , the stem of the parent word (usually a verb) + Greek -μα , suffix forming neuter nouns). Compare -ome comb. form. Greek -ωμα appeared in many words unconnected with medicine, e.g. ancient Greek δίπλωμα diploma n., as well as in medical terms. In the 16th and 17th centuries a number of medical terms passed into English, either directly or via Latin. These included terms for conditions of the eye (e.g. glaucoma n., staphyloma n.), terms for tumours (e.g. ecchymoma n., steatoma n.), and miscellaneous terms (e.g. sarcoma n., originally denoting a fleshy excrescence, condyloma n.). Further borrowings during the 18th and early 19th centuries in the medical field were mainly names of tumours (e.g. atheroma n., carcinoma n.). In the early 19th cent. formations in English (or scientific Latin) began to appear in which -oma was attached to Greek or Latin first elements. Apart from the early dacryoma n., denoting an eye condition, virtually all these terms denoted types of tumour, probably on the model of carcinoma n. and similar earlier loanwords, and perhaps also under the influence of sarcoma n. which had acquired the sense ‘tumour’ by this date. Early examples include hygroma n., lipoma n., and melanoma n. The combining form continues to be highly productive.