IPA: //ˌfoʊtoʊˈaɪənaɪzɪŋ//
KK: /ˈfoʊtoʊˌaɪənaɪzɪŋ/
Relating to a process that causes atoms or molecules to lose electrons due to the absorption of light.
The photoionizing radiation from the star affects the surrounding gas clouds.
Photoionizing → It is formed from "photo-" (from Greek "phōs", meaning light) and "ionizing" (from "ion" which comes from Greek "ion", meaning going or to go, combined with the suffix "-ize" meaning to make). The term describes the process of making ions through the action of light.
Think of 'light' ('photo-') causing something to 'go' or change into ions ('ionizing'). This helps you remember that photoionizing refers to the process of light creating ions.
No commonly confused words.