noun. A diatomic molecule that exists only when one of the atoms is in an excited energy state, especially one whose atoms are the same chemical element.

noun. Any diatomic molecule, at least one of whose atoms is in an excited state

"The experimental procedure, called photo-refractive keratectomy (PRK) and performed only by ophthalmologists, uses a new "excimer" laser to treat moderate degrees of nearsightedness (myopia)."

Timur  brimmer  dimmer  glimmer  grimmer