processionary

adjective

of, relating to, or moving in a procession

noun

a processionary moth

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

Examples from the Web for processionary

Historical Examples of processionary

So says the Processionary, who every evening spends his little capital of silk on enlarging a shelter that is often new to him.
Insect Adventures
J. Henri Fabre