Bumping is when an employer moves an employee whose role is redundant into a more junior colleague’s job, instead of dismissing them, so that the redundancy effectively falls on the junior role. There’s no automatic right to be bumped, but a reasonable employer will normally at least consider it, even if you never raise it yourself.
In practice
In Mirab v Mentor Graphics (UK) Ltd, a sales director argued his employer should have considered bumpingBumping is when an employer moves an employee whose role is redundant into a more junior colleague's job, instead of dismissing them, so that the redundancy effectively falls on the junior role. There... him into a more junior colleague's role instead of making him redundant outright.
See also