Brønsted base

https://doi.org/10.1351/goldbook.B00745
A molecular entity capable of accepting a hydron (proton) from an acid (i.e. a 'hydron acceptor') or the corresponding chemical species. For example: OH, H2O, CH3CO2, HSO4, SO42−, Cl .
See also: conjugate acid–base pair
Source:
PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1091 (https://doi.org/10.1351/pac199466051077)