Dictionary / Vocabulary / 火勢
かせい
force of a fire; force of flames
薪が足りず、はやくも火勢が衰えはじめた暖炉。
The fireplace, lacking firewood, flames already starting to lose their vigour.
暖炉には薪が足りず、早くも火勢が衰え始めている。
Without enough wood on the fire, the flames are already beginning to die down.