3) Something you made up one day to feel speshul. E.g. "semiqueer-bi-spirit-shemale". May use made-up pronouns such as "xe", "ze", "schlee", "nflgsufgshuihousu", etc. Anyone who finds this ridiculous is a bigot and is literally Hitler.
A noun can have one of three genders, masculine, feminine, and neuter. Gender is never male or female; that is sex.
The gender of a noun may have little or no relation to the sex of its bearer. For example, in German, the word for dog is der Hund, which has masculine gender. A dog may be male or female, but the word for dog has masculine gender.
Radical feminists, effeminate men, and extremely ignorant people use the word to mean sex. They also ignorantly believe that the pronoun HE, when used to refer to someone of unknown sex, is offensive. Instead, they ignorantly and incorrectly use the word THEY to refer to a single person of unknown sex. Notice that French, German, Spanish, and other people have no trouble at all distinguishing sex and gender. A German is never offended by the word ER used to refer to someone of unknown sex, even though ER also means HE. That's because Germans are intelligent enough to know the difference between gender and sex, and that gender may have little to do with sex.
Even well-meaning organizations ask for you gender on applications now, but only out of ignorance. They surely want to know if you are male or female, not whether you enjoy eating butt or prancing on floats in parades.