Greek astronomer (7)
I believe the answer is:
ptolemy
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">greek astronomer</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for ptolemy that I've seen before include "Greek astronomer; Greco-Egyptian ruler" , "Egyptian king or astronomer" , "Egyptian ruler; Greek astronomer" , "Ancient astronomer" , "Alexandrian astronomer" .)