If you say that someone relapses into a way of behaving that is undesirable, you mean that they start to behave in that way again.
例句
'I wish I did,' said Phil Jordan, relapsing into his usual gloom...“我要是那樣做了就好了，”菲爾·喬丹說道，又像往常一樣消沉起來。It is by no means clear that the financial markets will not relapse into panic.現在還不能確定金融市場不會重新陷入恐慌。
VERB
舊病復發;再次發病
If a sick person relapses, their health suddenly gets worse after it had been improving.
例句
In 90 per cent of cases the patient will relapse within six months.90%的病人在6個月內會再次發病。
英漢詞典釋義
n.
再度惡化;舊病復發；故態復萌
After making some progress, he suffered a relapse.他的病好了一點,又復發了。A wide range of emotionally stressful events may trigger a relapse.多種令人情緒緊張的事情都可能引起舊病復發。Even in relapse there will be times when the patient’s general condition improves.即便在復發期間，病人仍會有好轉的時候。
vi.
再度惡化;故態復萌
Cameron had relapsed into silence again.卡梅倫再度陷于沉默。She stopped using drugs for a month, but then relapsed.她一個月沒吸毒, 但后來又吸起來了。