also boohoo, 1520s, originally of laughter or weeping (now only of weeping); see boo.
Examples from the Web for boo-hoo
Upon completion of the song all children return to their own seats, singing— Boo-hoo!Dramatized Rhythm Plays|John N. Richards
And then it was boo-hoo, you know, same as women will when a thing ain't jest according to their liking.The Best Short Stories of 1919|Various
I used to long to throw myself in her lap and boo-hoo on her shoulder!The Dragon's Secret|Augusta Huiell Seaman
His boo-hoo might have been heard for miles, and the king naturally desired to stop it.The Old-Fashioned Fairy Book|Constance Cary Harrison
Monsieur, we—boo-hoo—we asked that barber man over there to let us get warm in his store and—and—he wouldn't do—it—boo-hoo!Standard Selections|Various