throwaway
adjective [ before noun ] uk/ˈθrəʊ.ə.weɪ/ us/ˈθroʊ.ə.weɪ/
一次性使用的，用后即弃的
made to be destroyed after use
We live in a throwaway society (= one in which things are thrown away as soon as they have been used). 我们生活在一个充斥着一次性物品的社会。
throwaway comment/line/remark 信口而作的评论／即兴的台词／脱口而出的话
something that someone says without thinking carefully and is not intended to be serious