Boop:

Boop is a player term for using an ability or attack to knock an enemy backward, off a ledge, or out of position.

In Overwatch 2, boops matter because they can secure environmental eliminations, interrupt enemy movement, and create space for a team. The term is often used for heroes with knockback effects, such as Lucio or Doomfist, and can also describe a well-timed shove from another source.