Green’s Dictionary of Slang

boohoo v.

[echoic]

(orig. US) to whinge, to complain.

[US](con. c.1840) ‘Mark Twain’ Huckleberry Finn 85: Next day back comes old Finn, and went boo-hooing to Judge Thatcher to get money to hunt for the nigger.
[US]New Ulm Rev. (MN) 17 Nov. 6/3: When we asked [...] what hr reason was, she boohooed, ‘Me and my man had some troubles [...] but my man and me have made up’.
[Aus]Sydney Sportsman (Surry Hills, NSW) 13 Feb. 1/5: Kelly is the party who caused [...] the books to boohoo.
Wahpeton Times (ND) 6 Aug. 4/2: ‘Pa,’ boohooed the chastised son, ‘if I had let Willie Simmonds lick me, instead of me licking him, would you have whipped me just the same?’.
[US]J.B. Lowitz [perf. Alice Lloyd] ‘Bandy Legs’ 🎵 Because all the kids that live down on our block, / They tease me and make me boo-hoo.
St Joseph Obs. (MO) 5 Jan. 5/5: His shoes hurt his feet and he was tired [...] so he just boohooed to his heart’s content until he could pull his shoes off.
[US]E. Dahlberg Bottom Dogs 226: Jeremy used to [...] chortle out loud to himself; whenever he remembered how farmer Lawrence got high blood pressure and boo-hooed till it seemed he was going to bust, because Jeremy had given his pony that name.
[US](con. c.1900) J. Thompson King Blood (1989) 197: Sure, there was fellas that boohooed and whined about it.
R. Charles Brother Ray 18: No use boohooing for Mama. She wasn’t coming.
[US]Lillie May Glover q. in McKee & Chisenhall Beale Black & Blue 152: Now, sometimes things come over that TV, dances and things I used to do, and I lay here and just boohoo.
[Ire]L. McInerney Rules of Revelation 131: up. What was the point in boohooing over some decade-old arseholery.

In derivatives

boohooism (n.)

(orig. US) nagging.

[Aus]Bulletin (Sydney) 4 Aug. 12/3: In the ‘Tyranny of Tears’ Grace Noble, as a pretty little nagging wife, looks almost dainty enough to account for hubby’s long submission to boo-hooism.