gender gap
noun /ˈdʒendə ɡæp/
  /ˈdʒendər ɡæp/
 - the difference that separates men and women, in terms of attitudes, opportunities and status- Women have closed the gender gap in education in recent years.
- Progress on equal pay has slowed and the gender gap has widened again.
- Motivational factors may widen or narrow the gender gap in students' academic performance.