Biblical queendom (5)
I believe the answer is:
'biblical queendom' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for sheba that I've seen before include "Solomon was visited by this country's queen" , "Old Testament realm of queen visiting Solomon" , "Biblical Queen of . . . . . visited King Solomon" , "Ancient people of Yemen, Sabaeans" , "Queen in the Bible unnamed except for her country; Balkis or Bilkis in the Quran" .)