n. The tendency of cross-breeding to produce an animal or plant with a greater hardiness than its parents; hybrid vigour
the GNU version of the Collaborative International Dictionary of English
n. A figure of speech by which one form of a noun, verb, or pronoun, and the like, is used for another, as in the sentence: “What is life to such as me?”
The Century Dictionary and Cyclopedia
n. In grammar and rhetoric, same as enallage.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. (genetics) the tendency of a crossbred organism to have qualities superior to those of either parent
Word Usage
"It has a phenomenon associated with it called 'heterosis' - otherwise known as 'hybrid vigor.'"