“2-yr mean citedness” is the OpenAlex field summary_stats.2yr_mean_citedness (CC0): mean citations per paper over a two-year window. It is a raw bibliometric field, not a journal rating, and is not used for default ranking.
Materials Science73Pharmacology, Toxicology and Pharmaceutics45Biochemistry, Genetics and Molecular Biology33Immunology and Microbiology30Medicine29Engineering26Medicine: Medicine (General)1Science: Biology (General)1