If you say that someone or something purports to do or be a particular thing, you mean that they claim to do or be that thing, although you may not always believe that claim.
例句
...a book that purports to tell the whole truth.声称要讲述全部事实的一本书
英英词典释义
Adjective
1. commonly put forth or accepted as true on inconclusive grounds;
"the foundling's putative father""the reputed (or purported) author of the book""the supposed date of birth"