Sherpa originally meant the tribe in Nepal whose social custom was to provide humane and courageous mountain guides to outsiders. This tribe didn't use last names, so they were all referred to as Sherpas. To the Sherpa, all Himalayan peaks are sacred, so every tour holds ethical and religious meaning. Westerners picked up on this and use Sherpa to mean an assistant who knows more than the boss.
The G8 Sherpas meet several times before the annual meeting. Each Sherpa has the authority to set policy for the Head of State.
Someone capable of carrying a ridiculous amount of cargo while riding their bicycle, usually with a cigarette dangling from their mouths.
Did you see that guy carrying 6 cases of empties, an old television, three boxes of Lucky Charms a mannequin and a cage with a cockatiel in it? He's a total Bike Sherpa.