Green’s Dictionary of Slang

a general phr. of dismissal, derision; also as n.

1730		J. Miller Humours of Oxford II i: Pooh, pooh; all Flam, Madam.
1758		A. Murphy Upholsterer II i: Po, po, not a Jot of that.
1778		Thrale Thraliana i Mar.-Apr. 247: There came out a Copy of Arabick Verses on the old King's Death at Oxford;—presently by the same hand came out a copy of Phœnician Verses on the new Kings Accession or Marriage I forget which: Poh! Poh! says old Bates, I believe ’tis only the same Stuff turned bottom upwards.
1778		Thrale Thraliana i Mar.-Apr. 569: The old Woman who shews Sir Francis Drake's House shewed his Sword & Pistols used in the days of Elizabeth—Pooh Pooh says Munsey, these are nothing without the proper Illustrations: You ought to say this is the Sword with which Sir Francis Drake cut the Line; and this the Pistol with wch he shot the Gulf.
1812		Spirit of Irish Wit 158: Pooh; Pooh’ you pragmatical fellow.
1812		Spirit of Irish Wit 167: Poh! Po! my dear W— [...] you’ll only expose yourself and be laughed at.
c.1815		J.K. Paulding Bucktails (1847) II iii: Pooh, pooh, brother – ’tis nothing but the old English hospitality.
1818		A.N. Royall Letters from Alabama 4 Jan. 124: ‘Poh, poh,’ said the planter, ‘I don’t care a cent for the girls.’.
1844		Thackeray Barry Lyndon (1905) 169: Pooh, pooh! youths like you easily fire and easily despond.
c.1850		Peeping Tom (London) 26 104/3: What you say about ‘becoming respect’ is all ‘Pooh! pooh!’.
1853		S. Northup Twelve Years A Slave 156: ‘Poh, poh!’ sneered Tibeats.
1855		Delhi Sketch Bk 1 Mar. 28/2: Medicus: Pooh pooh that’s all my eye!
1881		‘’Arry on Woman Rights’ in Punch 2 Apr. 156/2: There was one or two chaps in the meeting as did ’ave a bit of a go, — / Tried the lofty pooh-pooh, but [...] them feminines chopped ’em up fine.
1883		J. Payn Thicker than Water II 246: Pooh! pooh! my good fellow.
1891		Nat. Police Gaz. (NY) 28 Feb. 2/3: Mr. Duff made light of her protests and replied ‘nonsense’ and ‘pooh, pooh’.
1893		J. Walsh [perf. Vesta Tilley] Fairly Knocked the yankees in Chicago 🎵 Next they threatened to they would shoot me but I simply said, ‘Pooh-pooh!’.
1916		P. Kyne Cappy Ricks 290: ‘They called your bluff?’ Mr Skinner challenged. ‘Pooh-pooh for you!’ Matt laughed.
2021		J. Ellroy Widespread Panic 194: Nasty Nat put down some poo-poo patter ‘UCLA ain’t the ghetto, sisters’.