Wikipedia does not have an article with this exact name. You may want to read Wiktionary's entry on "tawdry" instead.
The word Tawdry is derived from cheap and shoddy goods that were sold at "St Audrey's Fair"; "Audrey" being the name by which St Etheldreda was known. The fair was held annually during the Middle Ages on St Etheldreda's Feast Day (23 June) at Ely in Cambridgeshire, England.
That 70's Show Mrs.Forman says in season 7 episode 4 7min 31sec into episode.