expression, i-adjective
have no way of knowing; be completely ignorant of
Fixed expression meaning there is no means or way to know something. Often used when the speaker has no access to information.
彼が今どこにいるか、知る由もない。
I have no way of knowing where he is now.
その話が本当かどうか、私には知る
I had no way of knowing whether that story was true.