Lacuna
Lacuna : la·cu·na, [ləˈk(y)o͞onə], NOUN, an unfilled space or interval; a gap:"the journal has filled a lacuna in Middle Eastern studies" synonyms: gap · space · absence · lack · deficiency · blank. a missing portion in a book or manuscript. Context : The lacuna in Smith's theory partly reflects technical difficulties in modeling growth. "We Still Need Growth," National Review , p24, May 2, 2022.