ionisation > define

noun

• The condition of being dissociated into ions (as by heat or radiation or chemical reaction or electrical discharge. )
  • usage: "the ionization of a gas"
  • synonyms: ionization
• The process of ionizing; the formation of ions by separating atoms or molecules or radicals or by adding or subtracting electrons from atoms by strong electric fields in a gas.
  • synonyms: ionization