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to become completely chilled
スープはすっかり冷え切った。
The soup had gone completely cold.
長年の間に、夫婦の関係は冷え切っている。
Over the years, the couple's relationship has become completely cold.
冬に外に長く立っていると、体が冷え切る。
If you stand outside for a long time in winter, your body will get thoroughly chilled.