boo word
n.— «Whatever their politics may be, the students interviewed were not—by their own perceptions—“liberals.” The world [sic] “liberal” has for them become, to use the jargon, a “boo” word, even a term of accusation.» —“Annual Education Review: 17 Campus Whites Express Their Views” by Arnold Beichman New York Times Jan. 12, 1970. (source: Double-Tongued Dictionary)