Green’s Dictionary of Slang

knap v.

[var. on nap v.1 ]

1. (UK gambling) to use sleight-of-hand to cheat in dice-play.

[UK]Nicker Nicked in Harleian Misc. II (1809) 109: [They] wheedle him into play, and win all his money, either by false dice [...] or by palming, topping, knapping, or slurring.
[UK]C. Cotton Compleat Gamester 15: Another way the Rook hath to cheat, is by [...] Knapping, that is when you strike a Dye dead that it shall not stir [...] I have seen some so dexterous at knapping, that they have done it through the handle of a quart Pot, or over a Candle and Candlestick.
[UK]T. Lucas Lives of the Gamesters (1930) 137: He was not ignorant in Knapping, which is, striking one die dead, and let the other run a Milstone, as the gamester’s phrase is, either at Tables or Hazard.

2. (UK Und.) to swear, to take an oath.

[UK]J. Poulter Discoveries (1774) 43: He knaps quare; he swears false.

3. to arrest.

[UK]C. Johnson Hist. of Highwaymen &c 354: I try’d several Stratagems to knap him.
[UK]Nancy Dawson’s Jests 36: Here Nancy no more shall be knap’d for a gown.

4. (UK Und.) to steal, to take, to receive; thus knapper n., a thief; knap a clout, to steal a handkerchief; knap seven penn’orth, to receive a 7-year sentence; knap/nap the glim, glue, to catch venereal disease; knap the swag, to grab the plunder.

[UK]Head Eng. Rogue I 50: Knapper of Knappers, A Sheep-stealer.
‘Swaggering Jack’ Molly of the Mill 2: With daddles clean he’d slip between, / A croud, and knap a clout unseen.
[UK]Vaux Vocab. of the Flash Lang. in McLachlan (1964) 248: knap: to steal; take; receive; accept; according to the sense it is used in; as, to knap a clout, is to steal a pocket-handkerchief; to knap the swag from your pall, is to take from him the property he has just stolen, for the purpose of carrying it; to knap seven or fourteen pen’ worth, is to receive sentence of transportation for seven or fourteen years; to knap the glim, is to catch the venereal disease; in making a bargain, to knap the sum offered you, is to accept it; speaking of a woman supposed to be pregnant, it is common to say, I believe Mr Knap is concerned, meaning that she has knap’d.
[UK]London Mag. i 26: It was their husband’s object to knap their thimbles [F&H].
[UK]‘Take a Sight’ in Rummy Cove’s Delight in Spedding & Watt (eds) Bawdy Songbooks (2011) III 104: So Sukey he sought, but he knapt no luck / [...] / For she’d married that morning a brick making buck.
[UK] ‘Tale Of A Shift’ in Cuckold’s Nest 35: But now I’ve something else in view; / And soon you will have cause to rue, / For, by jingo, you have knapped the glue.
[UK]G.W.M. Reynolds ‘The House Breaker’s Song’ in Farmer Musa Pedestris (1896) 123: The richest cribs shall our wants supply – / Or we’ll knap a fogle with fingers fly, / When the swell one turns his back.
[UK]Hotten Dict. of Modern Sl. etc.
[UK]Hotten Sl. Dict.
[UK]Aberdeen Jrnl 5 Nov. 2/5: In one corner four boys are learning how to ‘knap a fogle fly’ — i.e., steal a handkerchief skilfully .
[UK]W.E. Henley ‘Villon’s Straight Tip’ in Farmer Musa Pedestris (1896) 176: Suppose you screeve, or go cheap-jack? / [...] / Or thimble-rig? or knap a yack? / Or pitch a snide? or smash a rag?

In phrases

knap a jacob from a danna-drag (v.) [jacob n.1 (2) + danna n. + drag n.1 (2b)]

(UK Und.) to steal the ladder from a nightsoil cart in order to use it for burglaries.

[UK]Vaux Vocab. of the Flash Lang. in McLachlan (1964) 249: knapping a jacob from a danna-drag: This is a curious species of robbery, or rather borrowing without leave, for the purpose of robbery; it signifies taking away the short ladder from a nightman’s cart, while the men are gone into a house, the privy of which they are employed emptying, in order to effect an ascent to a one-pair-of-stairs window, to scale a garden-wall, &c., after which the ladder, of course, is left to rejoin its master as it can.
[UK]Egan Grose’s Classical Dict. of the Vulgar Tongue [as cit. 1812].
knap the ding (v.) [ding n.1 ]

(UK Und.) to take or steal what has already been stolen.

[UK]Vaux Vocab. of the Flash Lang. in McLachlan (1964) 235: ding: to throw, or throw away; particularly any article you have stolen, either because it is worthless, or that there is danger of immediate apprehension. [...] to ding to your pall, is to convey to him, privately, the property you have just stolen; and he who receives it is said to take ding, or to knap the ding.
knap the stoop (v.) (also nab the stoop, nap...) [SE stoop, the position into which the prisoner is forced]

to be placed in the pillory.

[UK]G. Parker View of Society II 30: Sentencing some more to be crapped; others to lump the Lighter; and others to nap the Stoop.
[UK]Grose Classical Dict. of the Vulgar Tongue n.p.: To nab the stoop, to stand in the pillory.
[UK]Lex. Balatronicum [as cit. 1785].
[UK]‘An Amateur’ Real Life in London II 97: [He] has been an exalted character, having once been made inspector of the pavement,* or in other words knapp’d the stoop. [* Inspector of the pavement, or knapp’d the stoop—Cant terms for the pillory].
[UK]Egan Grose’s Classical Dict. of the Vulgar Tongue [as cit. 1785].