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]
(..) Your jailer, huh? Yeah, boy, I'm makin' such a great deal on you, You wouldn't believe it. You're a regular cash cow, kid. That plus $ million, I could probably retire by the time I'm years old. Look, you're gonna have to help me out a little bit here. (..)1993 Free Willy