Ion (noun)

1. An atom or molecule that has gained or lost one or more electrons, giving it a net electrical charge.
2. A subatomic particle that has a net electric charge resulting from the loss or gain of one or more electrons.

Origin:

From greek ion, going, from ienai, to go.

Examples:

1. The ionic bond is a type of chemical bond formed between ions.
2. The ionosphere is a region of the upper atmosphere that is ionized by solar radiation.
3. Ions in the air can cause static electricity.
4. The ions in saltwater can corrode metal.
5. Ions are important in many biological processes, such as nerve transmission and muscle contraction.