- Geology. produced under conditions involving intense heat, as rocks of volcanic origin or rocks crystallized from molten magma.
- of, relating to, or characteristic of fire.
- (of rocks) derived by solidification of magma or molten lava emplaced on or below the earth’s surfaceCompare sedimentary, metamorphic (def. 2)
- of or relating to fire
1660s, from Latin igneus “of fire, fiery,” from ignis “fire,” from PIE *egni- “fire” (cf. Sanskrit agnih “fire, sacrificial fire,” Old Church Slavonic ogni, Lithuanian ugnis “fire”).
- Relating to rocks or minerals formed by the cooling and hardening of magma or molten lava. Basalt and granite are examples of igneous rocks.
- Relating to the processes, such as volcanism, by which such rocks and minerals form.