What does the word sexist language mean?

Answer 1

It means that the language prefers one sex over the other in grammar. A good example is french. "Ils" is they plural in masculine, "Elles" is they plural in feminine. If you were in a crowd of a hundred girls and only one boy, it'd be referred to as "Ils" in favor of the boy. If you were in a crowd of 5 girls and 5 boys, you'd be referred to as "Ils". Only if it is a group of all girls, is it ever referred to as "Elles", thus it is commonly referred to as a "Sexist language".