There are multiple definitions:

1. Older Americans Act; i.e. above 60 years(English)

   • Aging, Gerontology/Geriatrics, Legal issues
   • https://www.nco…-americans-act/

2. Open Access agreement(English)

   • OA
   • Biomedical journals

3. oral antiplatelet agent(English)

   • Thrombocyte /thrombosis

4. oral antidiabetic agent(English)

   • BMI, DM, ESRD, SKP
   • Diabetes, Therapeutic approaches, Adverse effect, Kidney and adrenals, Pancreas
   • https://doi.org…eed.2015.08.028