To be sexist, racist, anti-semetic, sectarianist, ageist and every other adjective used to describe some form of discrimination.
All of these adjectives are contained within this word, no fewer.
Name derived from the 1980s/90s extra-terrestrial sitcom character.
Commonly used as an insult.
Person 1: Have you noticed how discriminatory Stephen has been towards everyone lately?
Person 2: Yeah. Let's call him Alf.