Was familiar with (4)
I believe the answer is:
knew
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">was familiar with</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for knew that I've seen before include "Was familiar with" , "Recognised" , "Was cognizant of" , "Understood" , "Was cognisant or aware of" .)