ignite v.

1660s, "pertaining to or resembling fire," from Latin igneus "of fire, fiery; on fire; burning hot," figuratively "ardent, vehement," from ignis "fire, a fire," extended to "brightness, splendor, glow;" figuratively "rage, fury, passion," from PIE root *egni- "fire" (source also of Sanskrit agnih "fire, sacrificial fire," Old Church Slavonic ogni, Lithuanian ugnis "fire"). Geological meaning "produced by volcanic forces" is from 1791, originally in distinction from aqueous. Earlier in the sense "fiery" were ignean (1630s), ignic (1610s).

also ingnitible, "capable of being ignited," 1640s; see ignite + -able. Ignite (adj.) "glowing with fire" is recorded from 1550s.

also re-ignite, "catch fire again; cause to catch fire again," 1823, from re- "again" + ignite. Related: Reignited; reigniting; reignition.