Two terms for "fire" are reconstructible for Proto-Indo-European: *h₁n̥gʷnis and *péh₂ur. They are usually considered in semantic opposition. The first term is usually masculine and refers to fire as something animate and active (compare Agni, the most prominent Old Indic deity), whereas the second term is neuter and refers to fire as something inanimate and passive, i.e. as a substance.
- Indo-Iranian: *Hagnis
- Latin: ignis
- Hittite: 𒀀𒀝𒉌𒅖 (akniš, “name of a deity”) (could be inherited, borrowed from Indo-Iranian, or unrelated)