Green’s Dictionary of Slang

1. foolish, stupid; also as n. see cite 1829 etc; note the proper noun that has been extrapolated in cit. 1853.

1637		N. Whiting Albino and Bellama 19: The Cyprian goddesse woo’d her sappey boy.
1670		2nd Pt Peoples Liberties Asserted 6: When unlimited Prerogatives have sprung up, like Mushromes out of the sappy Apprehensions [...] of inferior Officers [OED].
1673		M. Stevenson Poems 111: Nor are you Lilly like, but sallow, And sappy-countenanc’d.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1811		Lex. Balatronicum.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1829		London Standard 19 Jan. 3/4: Spoon — a sawney, a Johnny Raw, a rural, a goose, a pump, a sappy.
1833		Satirist (London) 2 June 5/1: The Hon. Mr. Sappy was (first cleaned then) kicked out of the Strangers Club.
1840		T. Haliburton Clockmaker III 58: Talkin’ cute, looks knavish; but talkin’ soft, looks sappy.
1848		Boston Blade 10 June n.p.: Can’t shine, Sappy, better look out.
1849		Sam Sly 24 Mar. 3/3: J—n B—ggs [...] generally known as Sappey, to leave off his childish ways, and be a man in manners if not in age.
1853		‘Cuthbert Bede’ Adventures of Mr Verdant Green (1982) I 5: The Sappeys of Sapcot, a family that were not renowned either for common sense or wordly wisdom.
1860		R.S. Surtees Plain or Ringlets? (1926) 39: One said, it was young Sir Stephen Sappy; another Captain Hubbub.
1877		‘Andro and his Cutty Gun’ in Laughing Songster 15: He ca’d me ay his bonny thing, / And mony a sappy kiss I gat.
1882		County Paper (Oregon, MO) 15 Sept. 2/6: Such words as [...] sappy for silly, scaly for shabby.
1894		Mirror of Life 24 Mar. 7/3: ‘Any fwesh awwivals today?’ asked young Mr. Sappy.
1899		F.E. Daniel Recollections of a Rebel Surgeon 145: I used in the sappy days of my adolescence, the ‘fuzzy’ days of my green youth,—to-to attempt poetry!
1908		‘O. Henry’ ‘Innocents of Broadway’ in Gentle Grafter (1915) 117: He has nominated you custodian of his bundle in the sappy insouciance of his urban indiscrimination.
1908		Truth (Brisbane) 12 Apr. 9/3: Kocking of a warey optic / Out for Johnneys sappy green. / Coves wot’s drunk and country Jossers.
1914		Ade ‘The New Fable of the Speedy Sprite’ in Ade’s Fables 37: Loretta found herself between an extinct Volcano of Political World and a sappy Fledgling whose Grandfather laid the cornerstone of Brooklyn.
1928		M.C. Sharpe Chicago May (1929) 97: This sappy fool wrote how he felt like a cad for leaving his regiment in time of war.
1934		(con. 1920s) J.T. Farrell Young Manhood in Studs Lonigan (1936) 271: They’d [...] put slugs in the collection box, and laughed until a sappy-faced usher kicked them out.
1942		W. Winchell On Broadway 19 July. [synd. col.] The Times, which has always been nice to Congress, had to express its disgust for the sappier members.
1953		F. Paley Rumble on the Docks (1955) 80: This hunt for Marchesi is makin’ everybody sappy.
1966		P. Boyle At Night All Cats Are Grey 171: Yon sappy creature from the Crooked Bridge that finished up in the Mental Office.
1987		King Tee & Mixmaster Spade ‘Ya Better Bring a Gun’ 🎵 Cause they walk in the street with intentions to meet / Some sappy lookin punk with Fila on his feet.
1993		I. Welsh Trainspotting 119: This daft-lookin wee cunt [...] lookin it us wi they fuckin sappy eyes.

2. (US) sentimental and mawkish.

1873		Sl. Dict. 277: Sappy [...] namby-pamby, milk-and-watery. ‘It’s such a sappy book.’.
1883		‘Mark Twain’ Life on the Mississippi (1914) 224: He was [...] much better company than the sappy literature he was selling. [Ibid.] 355: ‘Friendship’s Offering,’ and ‘Affection’s Wreath,’ with their sappy inanities illustrated in die-away mezzotints.
1884		H. Newton ‘Bai Jove’ 🎵 No intellect troubles the ‘Chappie,’ [...] He prefers to be more or less ‘sappy,’ / And delights in tinsel and show.
1902		Ade Forty Modern Fables 56: The Younger and more sappy the Listeners the more elaborate was his Discourse.
1910		‘O. Henry’ ‘The Girl & the Graft’ Strictly Business (1915) 97: Sign yourself ‘Mama’s Own Big Bad Puggy Wuggy Boy’ if you want any limelight to concentrate upon your sparse gray hairs. Get sappy.
1915		S. Ford Shorty McCabe on the Job 163: And Hackett Wells nods, smilin’ at her fond and sappy.
1923		O.O. McIntyre New York Day by Day 18 July [synd. col.] Those were indeed the sappy days.
1930		W.R. Burnett Iron Man 275: I wish you guys would lay off them sappy songs.
1953		F. Paley Rumble on the Docks (1955) 310: Aw! a mash note.It’s his sappy sister.
1958		E. Dundy Dud Avocado (1960) 13: A look of sappy sweetness that was sharply at odds with [...] his tough, wise-guy manner.
1973		H. Leonard Da (1981) Act I: Sappy days, eh?
1982		R. Dahl Revolting Rhymes n.p.: And made to sound all soft and sappy / Just to keep the children happy.
1991		W.T. Vollmann Whores for Gloria 78: It sounds kind of sappy I guess.
2002		‘Touré’ Portable Promised Land (ms.) 7: Part eternal child, part social crusader, part sappy sentimentalist.
2003		Mad mag. Nov. 63: A sappy, sluggish, 20-minutes-too-long film.
2011		J. MacArthur ‘Jack Rabbit Slim’s Cellar’ in Pulp Ink [ebook] Destiny sounds like a sappy love song.
2016		Guardian G2 10 Feb. 6/3: Collins biggest regret (apart from covering the sappy Mindbenders hit) is talking to the Sun about politics.
2019		C.D. Rosales Word Is Bone [ebook] ‘That old movie we watched wasn’t even as sappy as all that’.

3. (US, also sapped) drunk.

2003

Drunktionary 🌐 ‘Sap’ is booze. Sapped. Sappy.