Today's Parola del Giorno is the noun, la macchina mangiasoldi, which means slot machine.
It literally translates as money-eating machine.
The adjective, mangiasoldi, is always invariable.
You might also see la macchinetta mangiasoldi for slot machine, or you might also see the English word — la slot machine — used, too.
You can see the word used in its context below:
A mia nonna piace andare al casinò con le sue amiche. Lo scorso weekend ha giocato alle macchine mangiasoldi e ha vinto 1000 dollari!
My grandmother likes to go to the casino with her friends. Last weekend she played the slots and won 1000 dollars!