in the red 负债，亏空，亏欠，有赤字

【例句】
They had to sell the firm because for years they had operated it in the red.
由于这家公司几年来一直亏损，所以他们只好把它卖掉。

Their company has been in the red in recent years.
他们的公司近几年一直在亏损。