From Longman Dictionary of Contemporary Englishthrowaway remark/line/comment etcthrowaway remark/line/comment etcWORD, PHRASE, OR SENTENCEsomething that someone says or writes quickly, without thinking carefully about it It was only a throwaway comment. He claims people overreacted to a few throwaway lines in the article. → throwaway
Examples from the Corpus
throwaway remark/line/comment etc• Lopez says, a throwaway line for a throwaway job.• He thought the remark was melancholy, sadly philosophical, a throwaway line for an aimless afternoon. 