Wordnet 3.0
VERB (1)
1. 
 make level, square, balanced, or concentric; 
- Example: "true up the cylinder of an engine"[syn: true, true up]
WordNet (r) 3.0 (2006):
true up
    v 1: make level, square, balanced, or concentric; "true up the
         cylinder of an engine" [syn: true, true up]