Wordnet 3.0
NOUN (2)
1. 
 a high-speed motorcycle race on a public road; 
2. 
 the amount of fuel used up (as in a nuclear reactor); 
The Collaborative International Dictionary of English v.0.48:
burn-up \burn-up\ n.
   a high-speed motorcycle race on a public road. [British
   slang]
   [WordNet 1.5]
The Collaborative International Dictionary of English v.0.48:
burnup \burnup\ n.
   the amount of fuel used up (as in a nuclear reactor).
   [WordNet 1.5]
WordNet (r) 3.0 (2006):
burnup
    n 1: a high-speed motorcycle race on a public road
    2: the amount of fuel used up (as in a nuclear reactor)