Or·tho-No·vum .ȯr-thō-'nō-vəm trademark used for a preparation of norethindrone and either ethinyl estradiol or mestranol
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Or·tho-No·vum (or″tho-noґvəm) trademark for oral contraceptive therapeutic regimens containing norethindrone as the progestational agent and either ethinyl estradiol or mestranol as the estrogen component.Medical dictionary. 2011.