Word origin: from the old TV show, "The Beverly Hillbillies", about a family of rustic hill folk who strike oil on their land and become fabulously wealthy. They "load up the truck and move to Beverly... Hills that is, swimmin' pools, movie stars." The comedy series revolves around how out of place the family is in their mansion.
beverly hillbilly is defined as: 1) a person who is obviously out of their element; 2) a person unable to utilize an object properly, for whatever reason.
Example 1: The pampered white social worker looked like a beverly hillbilly as she climbed the rickety stairs of the tenement building to pay a call on one of her families on caseload.
Example 2: The suburban parents' poor choice of a top end camera for their 12-yr old became apparent in the casual way the boy tossed it around showed his beverly hillbillyism with it.