"Homer Defined" is the fourth episode of the third season of the American animated television series The Simpsons. It originally aired on Fox in the United States on October 17, 1991. According to executive producer Al Jean, Gewirtz's script ended up featuring one of the longest first acts (an act being the amount of time between commercial breaks) in the history of the show when the episode was completed. Gewirtz's script originally contained two uses of the word "ass", once from Bart ("bad influence, my ass") and once from Burns ("...kiss my sorry ass goodbye"). This was the first time a character in the show had used this word, and it led to problems with the network censors. However, in the first rerun of the episode, this decision was reversed, with Burns saying "ass" and Bart saying "butt". (The official DVD release and the Disney+ release contains the dialogue from the reruns.)
thumb|200px|Basketball player [[Magic Johnson was the first professional athlete to guest star on The Simpsons.]]
Basketball player Magic Johnson of the Los Angeles Lakers guest stars in the episode as himself. He was the first professional athlete to do so on the show. Johnson appears in two sequences: first in a scene in which he calls to congratulate Homer on saving the plant, and later in the episode during a basketball game when he "pulls a Homer" by accidentally getting the ball into the basket after slipping on the floor. The recording of the episode was done during the National Basketball Association's regular season, so the producers had a hard time scheduling Johnson's session. With the deadline approaching, the producers traveled to Johnson's home to record his lines. Lakers sportscaster Chick Hearn also guest stars in the episode, commentating on the game that Johnson plays.
Another guest star in the episode was actor Jon Lovitz, who voiced Aristotle Amadopolis and an actor on a soap opera. This was Lovitz's third appearance on the show.
Milhouse's mother, Luann Van Houten, makes her first appearance in this episode. She was designed to look very similar to Milhouse.
During the scene in which Grandpa and the other residents of the retirement home are watching Wheel of Fortune, there was originally going to be a joke about comedian Redd Foxx, but because Foxx died six days before the episode aired, the joke was removed out of respect for Foxx and replaced with the Wheel bit at the last minute.
Reception and analysis
In its original airing on Fox, the episode acquired a 12.7 Nielsen rating and was viewed in approximately 11.69 million homes. It finished the week of October 14–20, 1991, ranked 36th, down from the season's average rank of 32nd. It ranked second in its timeslot behind The Cosby Show, which finished 24th with a 15.5 rating. The episode tied with In Living Color as the highest rated show on Fox that week.
"Homer Defined" has received generally positive reviews from critics. The authors of the book I Can't Believe It's a Bigger and Better Updated Unofficial Simpsons Guide, Gary Russell and Gareth Roberts, described it as an excellent episode which added new depth to the show in the scene with Marge trying to convince Luann to let Milhouse play with Bart again. They added that Lisa's "faith in her heroic father makes a nice change", and said that the episode's ending, in which Homer enters the dictionary, "is most satisfying". Nate Meyers of Digitally Obsessed rated the episode a4 (of 5), writing that he enjoyed the Homer story but found the Bart and Milhouse subplot more interesting. He added that "Milhouse's mom won't allow him to play with Bart because she thinks Bart is a bad influence. It's rare for the show to allow Bart to feel genuine emotion, but there is plenty of it in this episode that makes for a nice character oriented story."
Johnson's performance has also been praised. In 2004, ESPN released a list of the top 100 Simpsons sport moments, ranking his appearance at number 27. Sports Illustrated listed Johnson's cameo as the fifth best athlete guest appearance on The Simpsons. Meyers wrote that the episode "makes a lot of good points about the public making heroes in a rash, hysterical manner", and this point is made "with an amusing cameo by Earvin 'Magic' Johnson". Johnson's appearance was broadcast on CNN's Sports Tonight the day before the episode originally aired, and host Fred Hickman said he did not find it humorous. In the book, Gray says this scene is used by the show's producers to criticize "how often the news is wholly toothless, sacrificing journalism for sales, and leaving us not with important public information, but with America's Favorite Pencil".