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]
(..) -Actually, I minored in psychology. -Nice. -Okay, kiddo, fire me. -Ryan. Well, since she's gonna be doing this on a regular basis, don't you wanna know if she can fire somebody? -She's fired Ned. -My dog can fire Ned. Fire me. -You don't need to do this. (..)2009 Up in the Air