An expression originating from the Central Coast of California, particularly in Chicano jargon. Although similar to the widely-popular term "hella" of Northern California, it is used in descriptions as a replacement for adjectives such as "crazy" or "big" instead of adverbs such as "really" or "very" to emphasize astonishment, jealousy or sarcasm.
Damn! Mean ol' car. All fancy and shit.
He's a mean ol' player.
There was this mean ol' sale at Walmart.