A person who discriminates on grounds of sex; someone who practises sexism.(noun)
Unfairly discriminatory against one sex in favour of the other.(adjective)
Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License
Use "sexist" in a sentence
"I was in an environment full of testosterone and chaotic male hormones, and the word sexist had not yet been invented."
"Feel free to use the term sexist in the contest of Wolcott."
"In an effort to enlighten ourselves, we searched the term "sexist" on several stock photography sites, and we came up with some fairly resolute results."