supertruck

noun

a fast powerful truck used in truck racing
a very large truck used for transporting heavy loads in quarries and other heavy engineering sites, but which is too large for use on public roads

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012