- An atom or group of atoms that have a positive or negative electric charge due to a gain (negative charge) or loss (positive charge) of one or more electrons. Atoms with a positive charge are known as cations; those with a negative charge are anions.
Definition from: MeSH via Unified Medical Language System at the National Library of Medicine
- 1: An atom or group of atoms that carries a positive or negative electric charge as a result of having lost or gained one or more electrons.
2: A charged subatomic particle (as a free electron).
Definition from: Merriam-Webster's Medical Dictionary by Merriam-Webster Inc.
See also Understanding Medical Terminology.