β-elimination

synonym: 1,2-elimination
https://doi.org/10.1351/goldbook.08150
Transformation of the general type \[\ce{XABY -> A=B + XY (or X + Y, or X^{+} + Y^{-})}\] where the central atoms \(\ce{A}\) and \(\ce{B}\) are commonly, but not necessarily, carbon.
Source:
PAC, 2022, 94, 353. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 2021)) on page 376 [Terms] [Paper]