“渐渐衰弱的”可以用英语表达为 “gradually weakening” 或 “waning gradually” ，具体使用哪个表达可根据语境和搭配来决定。例如：
* His health has been gradually weakening over the past few years.（过去几年里，他的健康状况一直在渐渐衰弱。）
* The light was waning gradually as the sun set.（随着太阳下山，光线渐渐衰弱。）