“作为借口”常见的英文表达有：as an excuse 或 serve as an excuse。
as an excuse：这是一个较为简洁和常用的表达，直接说明某事物被用作借口。例如：He used his busy schedule as an excuse for not attending the meeting.（他以工作繁忙为借口，没有参加会议。）
serve as an excuse：强调某事物起到、充当借口的作用，语义上稍显正式或强调其功能性。例如：His poor health served as an excuse for his poor performance at work.（他身体不好成了他工作表现不佳的借口。 ）