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to be mixed; to be blended with; to be combined
to associate with; to mingle with; to interest; to join
喜びに悲しみが雑じった複雑な気持ちだ。
It's a complex feeling of joy mixed with sadness.
砂利に小石が雑じっているのが見える。
I can see pebbles mixed in with the gravel.
彼の声には怒りと悲しみが雑じっていた。
His voice was mixed with anger and sadness.