"Fag" is used twice in a derogatory and mean manner, but it is discouraged.
The word prick is used about 5 times. It is usually paired with other words like "miserable prick" or "major league prick".
The main running gag is Frank Murphy, the father and the protagonist of the show. He often says "I will put you through that fucking wall", and he typically says this to his two sons, Bill and Kevin.
Strong swearing throughout including "fuck", "motherfucker", "shit", "bullshit", "cunt", "cock", "ass", "asshole", "bitch", "slut", "whore", "ho", "cock", "twat", "tit", and more.
"Cunt" is sometimes said. Mostly in Season 2 and 3, but it is only used about 5 or 6 times.
The term "dildo" is used as an insult.
Almost any profane, racial, homophobic or xenophobic term one can think up is in this show.
Season 1: 105 f-words, 86 s-words, 1 c-word. Season 2: 209 f-words, 2 c-words, 124 s-words. Season 3: 240 f-words, 106 s-words, 2 c-words. Season 4: 205 f-words, 117 s-words, 2 c-words.
Frequent uses of "fuck" and "shit" are often used in front of, and by young characters as well as teenagers.
A few middle fingers.