a person at work that doesnt really work but makes it look he does.
All that guy does is walk around the office and talk to people and carry stuff in his hands so that he looks busy, hes such a johnnycab.
Verb: Getting a ride from friends or friends of friends because you don't have a car, or you're too cheap to pay for gas or a real cab.
Noun: A person who allows themselves to be used as free transportation without payment.
I blew all my money in Vegas, and had to Johnnycab my way home.
He doesn't even own a car, he just Johnnycabs wherever he needs to go!
"Are they dating?"
"No, he's her Johnnycab and is totally getting used."