Both can be translated as:
There are some clear differences between the two meanings of Fire in Japanese: 火 (ひ — flame, firelight) vs 火事 (かじ — on fire, ablaze)
言葉 (ことば • kotoba)
言 (koto) was previously the main term for word
The 葉 (ba) may have been added to differentiate from 事 (koto, thing).