adj. Having the quality of irrupting or making irruptions.
the GNU version of the Collaborative International Dictionary of English
adj. Rushing in or upon.
The Century Dictionary and Cyclopedia
Bursting in; rushing in or upon anything.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adj. of igneous rock that has solidified beneath the earth's surface; granite or diorite or gabbro
Word Usage
"They are unusual in that they do not 'migrate' south during the winter, but they do undergo 'irruptive dispersal', that is moving out of their breeding areas when their main prey, the lemming, suffers a declining population."