—used to express contempt or disapproval or to startle or frighten
plural boos
1
: a shout of disapproval or contempt
2
: any utterance at all
—usually used in negative constructions
never said boo
booed; booing; boos
: to deride especially by uttering a prolonged boo
: to express disapproval of by booing
the crowd booed the referee
plural boos
US slang
: a romantic partner : sweetheart, honey
Your parents might keep a sharp eye on potential partners and your besties may lay down difficult "friend tests," but only one real opinion on your new boo truly matters: what your dog thinks of them.—Jaime Lees
This has left me skeptical of all new relationships—including my new boo.—Griffin Wynne
Cite this Entry
“Boo.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/boo. Accessed 7 Jul. 2026.
Copy CitationLove words? Need even more definitions?
Merriam-Webster unabridged
