NOUN (2)

1. a hand tool for driving screws; has a tip that fits into the head of a screw;

2. a cocktail made with vodka and orange juice;

The Collaborative International Dictionary of English v.0.48:

Screwdriver \Screw"driv`er\, Screw-driver \Screw"-driv`er\, n.
   A tool for turning screws so as to drive them into their
   place. It has a thin end which enters the nick in the head of
   the screw.
   [1913 Webster]

WordNet (r) 3.0 (2006):

screwdriver
    n 1: a hand tool for driving screws; has a tip that fits into
         the head of a screw
    2: a cocktail made with vodka and orange juice