setscrew (n.)

  1. a screw that is used to adjust the tension on a spring

  2. a screw (often without a head) that fits into the boss or hub of a wheel or cam etc. and prevents motion of the part relative to the shaft on which it is mounted

The dictionary is based on the WordNet Electronic Lexical Database.
WordNet 3.0 Copyright 2011 by Princeton University. All rights reserved.