0 (actions based on) the belief that the members of one sex are less intelligent, able, skilful, etc. than the members of the other sex, especially that women are less able than men: --
The university has been accused of sexism because it has so few women professors.
1 actions based on a belief that particular jobs and activities are suitable only for women and others are suitable only for men: --
Sexism continues to keep girls out of plumbing, electrical, and construction trades.
2 treatment of men and women based on the belief that particular jobs and activities are suitable only for men and others are suitable only for women: --
The company is facing accusations of sexism in its recruitment policy.