The engine suddenly 'roared (back) to life'. [=it made the loud sound of an engine and began running well]
The audience 'roared' with laughter. [=the audience laughed loudly for a long time]
The fans were 'roaring' [=yelling and cheering loudly] after their team scored.
(..) It stomps towards you. - Boom! - Fireball him! - Another stomp, boom! - Cast Protection. - He roars in anger! - - Fireball! - - Oh, shit! - Where'd it go? (..)2016 TvShow: Stranger Things Title: Chapter One: The Vanishing of Will Byers Season: 1 Episode 1