Incendiary means made to start fires, or designed to inflame feeling. An incendiary device, incendiary remarks, an incendiary bomb.
The military sense is technical and the figurative one is a warning: incendiary language is language calculated to start something. Incendiary weapons against civilians are restricted by international convention, and the arguments about that are live.
1adjectiveincendiaryMade to start fires, or designed to inflame feeling.
“Police found an incendiary device hidden under the shop's back door.”
incendiary is a quality.
Latin incendiarius comes from incendium, a fire, from incendere, to set alight.
Latin
incendiārius — setting alight
Old French
incendiaire
Middle English
incendiarie
English, today
incendiary
Built from
From Middle English incendiarie, from Old French incendiaire, from Latin incendiārius (“setting alight”), from incendium (“destructive fire”), from incendō (“to set on fire, kindle”), from in- (“into, in, on, upon”) + candeō (“to be hot”).
Etymology from Wiktionary, CC BY-SA