The word "repel" in science has a very specific meaning, and it refers to the mutual pushing away between two objects or particles. It's a key concept in understanding forces and interactions in the physical world.

Here's a breakdown of its meaning:

* Repulsion: A force that pushes two objects or particles apart. This force acts in the opposite direction of attraction, which pulls objects together.

* Electrostatic Repulsion: Occurs between objects carrying the same type of electric charge (either both positive or both negative). Like charges repel each other.

* Magnetic Repulsion: Occurs between two magnets with the same poles facing each other (both north or both south). Like poles repel each other.

* Other forms of Repulsion: Repulsion can also happen due to other forces, like the strong nuclear force which repels protons within the nucleus of an atom.

In short, "repel" in science means to push away due to a force acting between objects or particles.