Definition of photoionize in US English:

photoionize

(also photoionise)

verb

Astronomy Physics
  • with object To ionize by the agency of electromagnetic radiation.

Origin

1930s; earliest use found in Proceedings of the Royal Society of London. From photo- + ionize, after photoionization.

Pronunciation

photoionize

/ˌfəʊtəʊˈʌɪənʌɪz/