Excited State
Definition
When an atom has absorbed energy and one of its electrons has jumped to a higher orbital: a temporary, high-energy condition.
Technical definition
An excited state is any electronic state of an atom or molecule with energy above the ground state, produced when an electron absorbs a photon or energy from a collision and moves to a higher orbital. Excited states are typically unstable and decay by emitting light.
Example
Neon signs glow because electricity excites neon atoms, and the electrons release orange-red light as they fall back to the ground state.
Common confusion
An excited atom is not ionized. The electron moved to a higher orbital but is still bound to the atom; removing it entirely would be ionization.