“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.
Social Sciences4Biochemistry, Genetics and Molecular Biology2Earth and Planetary Sciences2Environmental Science2Medicine2Medicine: Medicine (General): Computer applications to medicine. Medical informatics1Medicine: Medicine (General): Medical technology1