warming sake
燗 centers on applying gentle heat to sake to bring out its flavor and warmth. The meaning is specific to warming sake.
燗 combines 火 (fire) with 閒, which likely contributes the sound and the idea of a gap or interval, suggesting the controlled application of heat. The exact historical development of the compound is uncertain.
The left side is fire 火, and the right side 閒 looks like a gate 門 with a moon 月 inside. Picture a gate to a cozy room where a fire gently warms sake under the moonlight.
For ラン, imagine running a warm sake bottle under a gentle flame: run -> ラン, and the fire warms the sake.
warming up sake; warmed sake
hot sake
warmed sake
warmed sake (to around forty degrees Celsius)
moderately heated sake
sake warmed to human body temperature (approx. 37 degrees C)
to warm up sake
leftover sake (which has cooled)
bottle used for warming sake
person in charge of warming sake in a bar