(plural: ‘incendiaries‘; pronunciation: the letter ‘i’ rhymes with the letter ‘i’ in “ink” — for the right pronunciation of this word, please click here)
a person who burns things, especially public property, down or causes trouble by violent means, usually related to burning down things, which is a punishable crime;
a person who causes/stirs up trouble in a place; a factionist; an agitator (not necessarily burning down something directly, but making people get excited, usually regarding a political issue, and causing trouble),
The police have identified the incendiary that torched the heritage building and are on the look out for a young man of 25 years of age.
Wherever there is a mass protest, there are incendiaries present whose sole purpose is to burn down things irrespective of the cause of the protest, turning the protest into a riot.
Jack and Mike are incendiaries in our community; always trying to instigate the public to take up arms and rebel against anybody and for anything.