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]
(..) - I just saw him. He had blood on his hands. He's lost his fucking mind. I don't know what we're doing here, boys. He's not including his regular guys. But I'll tell you something. Sooner or later he's gonna find out who I am and he's gonna fucking kill me. - I know it. He's gonna fucking kill me! (..)2006 The Departed
(..) ...through the mercy of God rest in peace. Amen. So what do I do? There's money behind this operation. You won't be paid as a regular cop... ...but there's a bonus involved. Tax-free. We can't conceal that you were a trainee. You'll be convicted of a crime. We're thinking a guilty plea (..)2006 The Departed