poormouth, n. — Green’s Dictionary of Slang

poormouth n.

(US) the act of belittling, complaining etc; usu. in phrs. below.

1959		D. Hewett Bobbin Up (1961) 108: We never cried poor mouth in our lives.
1965		L. Dunne Goodbye to The Hill (1966) 30: ‘Ah, I’m not well,’ he moaned, doing a good copy of my poor mouth.
1995		Sun. Indep. (Dublin) 3 Dec. n.p.: They played the poor mouth despite mounting a well-funded, highly devious, and very effective campaign [BS].

make (a) poor mouth (v.) (also put on a poor mouth, put up...)

(Irish/US) to complain, to whinge, to slander, to belittle or downplay.

1822		Blackwood’s Mag. Sept. 307: It’s no right o’ you to be aye making a puir mouth [F&H].
1884		Daily News in Ware (1909) 204/1: The Irishman, putting a poor mouth on his position, declared that at his house ‘whin they had a red herring it was Christmas Day wid ’um’.
1905		H. Green Actors’ Boarding House (1906) 35: I keep puttin’ up a poor mouth, an’ they think I simply gotta git the coin.
1908		L. Doyle Ballygullion 195: Ye had only to go an’ make a poor mouth to Sammy an’ he’d ha’ give ye the coat off his back.
1934		Z.N. Hurston Jonah’s Gourd Vine (1995) 84: Don’t come puttin’ up no po’ mouf tuh me, Lucy. Git ou mah face.
1966		P. Boyle At Night All Cats Are Grey 170: Four pages of excuses for not sending home any money. She was aye one for putting on the poor mouth.
1995		S. Connaughton Border Diary n.p.: Like all actors David put a poor mouth on it. ‘Oh you know, just pulling the divil by the tail.’ [BS].
2017		Negus Who Read 3 July 🌐 You can [...] get 1.204 cans of NuGrape for like $1.28, so please don’t play the poormouth card.

talk (a) poor mouth (v.) (also hawk the poor mouth)

(Irish/US) to deny one’s assets or advantages.

1941		in H. Wentworth Amer. Dial. Dict. (1944) 469/1: College professors are supposed to talk po’ mouth.
1945		A. Kober Parm Me 92: All you did was to talk a ‘poor mouth’ about how business was bad.
2015		L. McInerney Glorious Heresies 117: The bitch had always maintained she didn’t have a bob to her name but with only one kid and a frame that suggested she only ate on Thursdays, it was obvious she was hawking the poor mouth.