IPA: //ˌmʌltiˈfoʊtən//
KK: /mʌltiˈfoʊtən/
Relating to or involving more than one photon, which are particles of light.
The multiphoton process allows for advanced imaging techniques in microscopy.
Multiphoton → It is formed from "multi-" (meaning many) and "photon" (from Greek "phōs", meaning light). The word describes a process involving many light particles or photons.
Think of 'many' ('multi-') light particles ('photon') working together — that's what multiphoton means.
No commonly confused words.