English Translation
They were stuck in the elevator for four hours.
rester (v)
5. Se maintenir, continuer à être dans la même position, le même état : Rester debout. Rester jeune. Je reste votre ami.
Synonyme :
demeurer
Larousse online
Rester in this sentence doesn’t appear to add meaning, only emphasizes the unchanging state of being stuck? As usual, please add to or correct this.