All 3 Uses

gender
in
Blood Brothers, by Nora Roberts
(Auto-generated)

Gage being drafted to make breakfast today is an example of the basics in non-gender-specific teamwork.†
p. 275.4 *

gender = male, female, or any of many trans categories
Non-gender-specific teamwork, he thought.†
p. 275.4
They'd gone back to gender groups.†
p. 288.1

Definitions:

(1) (gender as in: gender discrimination)
male or female

or (especially regarding self-identification): the state of being male, female, or in any of many trans categories

While the word sex can almost always be substituted for this meaning of gender, gender is typically used in reference to cultural or social differences, while sex is typically used for biological differences.
(2) (meaning too rare to warrant focus)
Less commonly, gender can refer to a grammatical categories. In some languages (not modern English), nouns that are not distinguishable by biological sex, can still have a feminine or masculine gender.