Entry from British & World English dictionary
noun (also processionary moth) (plural processionaries)
1A greyish moth whose caterpillars live communally in silken tents in trees, marching out at night in procession to feed, causing substantial damage.
- Family Thaumetopoeidae: several species, in particular the European pine processionary (Thaumetopoea pityocampa)
1.1 (also processionary caterpillar) The larva of the processionary moth.
Definition of processionary in: