Green’s Dictionary of Slang

buff v.1

[? SE buff, to ‘polish’ the truth]

1. (also buff it home) to brazen out.

[UK]Cleland Memoirs of a Woman of Pleasure (1985) 49: As knowing as she was of the town, as hackney’d as she was in buffing through all the dangers of her vocation.
[US]Aurora (Phila.) 23 Aug. n.p.: If we were as fond of fighting France as ever buffing Jackson, or big Ben, or the tinker of Cornwall were of entering the lists.
[UK]Lytton Paul Clifford III 126: Tell me, do you think the Grazier will buff it home?
[UK]Paul Pry 30 Sept. 180/2: We know all about his racing establishment at Stockwell [...] and how he buffed it before the late committee.
[US]Trumble Sl. Dict. n.p.: Buffing it home is swearing point-blank to anything, about the same as bluffing it, making a bold stand on no backing [F&H].
[Aus]Crowe Aus. Sl. Dict. 12: Buffing it Home, same as bluffing it; swearing point blank to anything.

2. to give evidence, to testify.

[UK]Lex. Balatronicum n.p.: buff. [...] To swear as a witness. He buffed it home; and I was served; he swore hard against me, and I was found guilty.
[UK]Egan Life in London (1869) 222: One of the coffee-shop party is tipping a Charley to buff it strong against tom and jerry.
[UK]‘The City Youth’ in Out-and-Outer in Spedding & Watt (eds) Bawdy Songbooks (2011) IV 140: The traps they buff it home the forty for to chop.
[US]Ladies’ Repository (N.Y.) Oct. VIII:37 316/1: Buff to, to swear to or against. Buff for, to swear in favor.
[Aus]Bell’s Life in Sydney 7 Feb. 2/7: He requested the policeman not to buff too strongly against him [...] ‘I am afraid you will cook my goose’.
[UK]Hotten Dict. of Modern Sl. etc. 12: BUFF, to swear to, or accuse.
[US]H.L. Williams Ticket-of-Leave Man 12: I’d as leaf have murder as a crack ‘buffed’ to me.
[UK]Hotten Sl. Dict. [as cit. 1859].
[UK]M. Williams Round London 96: What robberies are you going to buff me for?

3. to commit perjury, to swear falsely.

[UK]H.T. Potter New Dict. Cant (1795).
[UK]‘T.B. Junr.’ Pettyfogger Dramatized I i: He has buffed at least one thousand in my service.
[UK]G. Andrewes Dict. Sl. and Cant.
[UK]Flash Dict.
[UK]G. Kent Modern Flash Dict. 7: Buff, to – to swear falsely, to perjure.
[UK]Flash Dict. in Sinks of London Laid Open [as cit. 1835].
[UK]Duncombe New and Improved Flash Dict.
Mt Alexander Mail (Vic.) 28 Oct. 3/3: A man [...] would stato that he had been in possession of tho jewellery, and had; sold it in the open market. The consequence would most probably be that the prisoners would be discharged, there being no evidence of the property having been stolen. The species of fraud was what was known by the slang term ‘buffing’.

4. to inform against.

[UK]Hotten Dict. of Modern Sl. etc. 12: BUFF, [...] to peach upon.

5. (US drugs) to manipulate, to con, to threaten.

[US]L. Pettiway Workin’ It 135: They lose all morals, principles and respect [...] You know, buff somebody, buff the dude – suck somebody dick. Buffing up them guns. People have said they children are in hospital, all that kind of shit ... they mother died. People do that shit for hits.

In phrases

buff to the stuff (v.)

(UK Und.) to claim that stolen property is one’s own.

[UK]Morn. Post 18 Aug. 7/2: They were going to send some people to ‘buff to the stuff’, and if he and Ranger were to tell the magistrate that they had made enquiries and believed that the property to belong to these people, he would discharge them.

SE in slang uses

In phrases

buff out (v.) [? SE buff up or the addition of some form of buffer]

(US drugs) to adulterate a drug.

[US]H. Feldman et al. Angel Dust 124: We’d hit it or buff it out maybe three to one ration – three parts anoscitol corn sugar to one part PCP – and then market it as crazy coke or cannabinol. [Ibid.] 125: So-called THC, which I know to be PCP buffed out.
buff up (v.) [SE buff, to polish + buff adj.2 (1)]

(orig. US) to work out in the gym to improve one’s musculature.

[US]Bentley & Corbett Prison Sl. 31: Buff Up also Buffed To add muscle mass to one’s body by rigorous weightlifting exercises.
[US]F. Kellerman Stalker (2001) 104: Our conversations were strictly lightweight – buffing up our bods, how our workouts went.