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1. Produced under conditions involving intense heat
   "igneous rock is rock formed by solidification from a molten state; especially from molten magma";
   - pyrogenic, pyrogenous
    
2. (geology) produced by the action of fire or intense heat
   "rocks formed by igneous agents";
   - eruptive
    
3. Like or suggestive of fire
   "an igneous desert atmosphere";
   - fiery

See also: hot

Antonym: aqueous

Encyclopedia: Igneous