The buses run from 4 a.m. to midnight 'at regular intervals'. [=there is the same amount of time between buses]
It's nothing special, just a 'regular' [='basic'] stereo. = It's just a 'regular old' stereo.
He is one of the store's 'regular customers'. [=customers who shop at the store frequently]
(..) Old man Peabody owned all of this. He had this crazy idea about breeding pine trees. This is... This is heavy-duty, Doc. This is great. Does it run on regular unleaded gasoline? Unfortunately, no. It requires something with a little more kick. Plutonium. Plutonium. Wait a minute. Are you telling me (..)1985 Back to the Future