Cliff is a
postal worker, and
Norm Peterson's
best friend. He lives with his mother,
Esther Clavin (
Frances Sternhagen)—first in his childhood two-story house (which was
bulldozed in the sixth season's "The Last Angry Mailman" after Esther sold it to a convenience-store builder), and then in a
condominium (which first appears in the season 6 episode "My Fair Clavin") with a
sofabed. He is ridiculed by friends and enemies alike, including
Carla (
Rhea Perlman) and Norm, for his know-it-all attitude. He appears on
Jeopardy! in the season-eight episode "
What Is... Cliff Clavin?", where he wins $22,000 in the first two rounds with questions that favor him, but loses it all with a wrong answer in
Final Jeopardy (launching into a tirade which frightens host
Alex Trebek). Cliff has a few relationships (mostly short-lived and hopeless) with women. He then has a relationship with fellow postal worker
Margaret O'Keefe (
Annie Golden) since
Cheers seventh season (1988–89). When Margaret becomes pregnant with another man's child in 1993's "Do Not Forsake Me O My Postman", Cliff stays by her side as the baby's stepfather before Margaret returns to the child's biological father. In "The Barstoolie" (1985), Cliff meets his father, Cliff Clavin Sr. (
Dick O'Neill), who left Cliff and his mother years earlier when Cliff was still a child. Cliff later realizes that his father is a fraudster and a fugitive from justice, and will run off again. Cliff does not want to turn his father in; Cliff Sr. disappears, leaving his son devastated. In the 1993
series finale, Cliff finally receives a promotion. In "
The Show Where Sam Shows Up" (1995), an episode of the
Cheers spinoff
Frasier,
Sam (
Ted Danson) tells Frasier that Cliff has not left home since he read an article about
flesh-eating bacteria; however, Sam then discovers that Cliff is one of the other men with whom Sam's fiancé Sheila (
Téa Leoni) had had sex. In another
Frasier episode, "The Show Where Woody Shows Up", Woody tells Frasier that Cliff almost married a mail-order bride, but she decided to go back to
Bosnia after spending a few days with him. In another
Frasier episode, "Cheerful Goodbyes", Cliff has his retirement party at the airport bar; he had planned to move to Florida, but decides to stay in Boston (to Carla's dismay). == Reception ==