This is the 568th most frequent Italian word.
prossime
"Prossime" means "next" or "upcoming" (feminine plural).
Here, 'prossime' is an adjective describing 'settimane' (weeks), indicating they are 'upcoming' or 'next'.
Le prossime settimane saranno molto impegnative.
The upcoming weeks will be very busy.
In this sentence, 'prossime' describes 'ore' (hours), denoting they are the 'next' hours.
Durante le prossime ore, ci sarà probabilmente pioggia.
During the next few hours, there will probably be rain.
Here, 'prossime' is used as an adjective modifying 'fermate' (stops), suggesting they are the 'next' stops.