in·cen·di·ar·y / inˈsendēˌerē/ • adj. (of a device or attack) designed to cause fires: incendiary grenades. ∎  tending to stir up conflict: incendiary rhetoric an incendiary slogan. ∎  very exciting: an incendiary live performer.• n. (pl. -ar·ies) an incendiary bomb or device. ∎  a person who starts fires, esp. in a military context. ∎  a person who stirs up conflict.DERIVATIVES: in·cen·di·a·rism / -dēəˌrizəm/ n.

incendiary adj. and sb. XVII. — L. incendiārius, f. incendium burning, fire; see next and -ARY.