noun
remaining heat; residual warmth
Refers to heat that lingers after the source is gone, such as embers, a cooling pan, or a fever that has mostly subsided.
火を消しても、ストーブにはまだほとぼりが残っている。
Even after turning off the flame, there is still residual heat in the stove.
熱は下がったが、体にまだほとぼりがある。
The fever has gone down, but my body still feels warm.
noun
lingering excitement; residual commotion; afterglow of enthusiasm
Describes public attention, media buzz, or personal excitement that continues after an event has ended. Often used in the phrase ほとぼりが冷める (the excitement dies down).
事件のほとぼりが冷めるまで、しばらく静かにしていたほうがいい。
It's better to lie low until the commotion over the incident dies down.
優勝のほとぼりがまだ冷めやらない。
The excitement of the victory still hasn't subsided.
余熱 is more literal and often used for physical residual heat in engineering or cooking contexts, while ほとぼり can be used both literally and figuratively for lingering excitement.
Derived from 火 (ho, 'fire') + とぼり (tobori, 'dimming, dying down'), referring to the fading glow of embers. The exact historical derivation is uncertain.