Which word is true: " gehinnom " or " gehinnam" ?

https://en.m.wikipedia.org/wiki/Valley_of_Hinnom_(Gehenna)#:~:text=Eventually%20the%20Hebrew%20term%20Gehinnom,day%20is%20excluded%20from%20punishment

Gehenna /ɡɪˈhɛnə/; from Ancient Greek: Γέεννα, Geenna from גֵּי בֶן־הִנֹּם‎ gēi ben-Hīnnōm, also גֵי־הִנֹּם‎ gēi-Hīnnōm; Mishnaic Hebrew: גהנום‎/גהנם‎, Gehinnam/Gehinnom

In islam this word is ” Jahannam “, i want to know which hebrew version of this word is close to jahannam.