Electron affinity refers to the energy released when an electron is added to a neutral atom or molecule. Some synonyms for electron affinity include electronegativity, electron-attracting power, ionization energy, and electron gain enthalpy. Electronegativity is a measure of an atom's tendency to attract electron pairs towards it, while ionization energy is the energy required to remove an electron from an atom or molecule. Electron gain enthalpy, on the other hand, is the energy released when an atom or molecule gains an electron. All of these terms are related to the attraction between electrons and atoms, and understanding them is crucial for understanding chemical reactions.