From Longman Dictionary of Contemporary Englishroll something ↔ down phrasal verb1 roll a window downTTCOPEN to open a car window2 to unfold the ends of your sleeves or trouser legs so that they are their usual length He rolled down his sleeves and buttoned the cuffs. → roll→ See Verb table
Examples from the Corpus
roll down• He rolled his window down and awaited the boy, still laughing.• They wanted desks and tables with wheels that could be rolled up and down corridors.• They roll grenades down floors of cinemas and blow up women and kids: does your heart bleed about that, Trevor?• She did not observe a large tear rolling slowly down his cheek.• They rolled up and down perfectly and their presence obviated the need for curtains.• Wearing his scarlet flannel pad, he rolled majestically down the chute to the quay and everybody laughed and cheered.• It pitched a yard short, bit viciously and rolled back down the green shelf at the front of the green.• Mosquitoes began to gather, and Gary and I rolled our sleeves down to protect our arms. 