Sentence:  It is doubtful that Utopia is still widely read because More was medieval or even because he was a martyr - indeed , it is likely that these days many who read Utopia with interest do not even <WSD>know</WSD> that its author was a martyr . 
Meaning of the word marked with <WSD> tags:  be cognizant or aware of a fact or a specific piece of information; possess knowledge or information about