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to melt (and become soft or liquid)
to be enchanted (by); to be charmed; to be bewitched
このチーズは口の中でとろけるようだ。
This cheese seems to melt in your mouth.
バターがフライパンの熱でとろけてしまった。
The butter melted from the pan's heat.
彼女の笑顔を見て心がとろけそうだ。
Seeing her smile, my heart feels like it's melting.