Boo

Interjection

 * 1) A loud exclamation intended to scare someone, especially a child.  Usually used when one has been hidden from the victim and then suddenly appeared unexpectedly.
 * 2) A word used ironically in a situation where one might have scared someone, but said someone was not scared.  Not said as loudly as in definition 1.
 * 3) A word used by someone who is inherently scary, such as a ghost or a vampire, to make a weaker person who is scared stiff flee.  Usually used quietly, as with definition 2.
 * 4) An exclamation used by a member of an audience, as at a stage play or sports game, to indicate derision or disapproval of what has just occurred.

Noun

 * 1) A derisive shout made to indicate disapproval.
 * 2) 🇺🇸 A close acquaintance or significant other, derived from French beau.

Verb

 * 1)  To shout extended boos derisively.
 * 2)  To derisively shout extended boos at.
 * The protesters loudly booed the visiting senator.

Thesaurus
Bronx cheer, Mary Jane, bird, booing, cannabis, catcall, give the bird, give the raspberry, grass, hiss, hissing, hoot, pooh, pooh-pooh, pot, raspberry, razz, tea, the bird, weed, whistle at