boo C2+ Topic:Communication Also spelled Boh US /bu/ UK /buː/ See IPA manual Homophones bu /bu/ Meanings 1 intj an exclamation to startle or to express disapproval The crowd let out a long boo when the referee blew his whistle. Thesaurus Synonyms 1 intj · an exclamation to startle... jeerhisshootcatcallheckle ↔ Opposites cheerapplaudclap Word family Derived forms booerbooing Etymology AI details Imitative, expressing disapproval or used to startle; recorded from the 19th century, echoing a lowing or jeering sound. boo onomatopoeic View etymology graph -> Topics Communication External links Cambridge Dictionary Wiktionary Google Images # boo **Type:** Word **Level:** C2+ **Part of speech:** intj **IPA (US):** /bu/ **IPA (UK):** /buː/ ## Meanings 1. an exclamation to startle or to express disapproval ## Examples - The crowd let out a long boo when the referee blew his whistle. ## Synonyms - jeer - hiss - hoot - catcall - heckle ## Antonyms - cheer - applaud - clap ## Derived Forms - booer - booing ## Roots and Affixes - Root: boo ## Etymology Imitative, expressing disapproval or used to startle; recorded from the 19th century, echoing a lowing or jeering sound. ## AI Etymology Boo is imitative, expressing disapproval or used to startle; recorded from the 19th century, echoing a lowing or jeering sound. The historical trail runs through onomatopoeic boo. In modern use it means an exclamation to startle or to express disapproval. Derived formations include booer, booing. ## Topics - Communication markdown