While people have expressed displeasure publicly since ancient times, the English word boo was first used in the early 19th century to describe the lowing sound that cattle make. Later in the 1800s, the word came to be used to describe the disapproving cry of crowds. Hoot, another onomatopoeic English word, was used as early as 1225 to describe the same phenomenon. (Ancient Greek and Latin both contain words resembling boo that mean "to cry or shout aloud," though there is no known etymological connection to the modern English word.)
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