1. in senses of display, ostentation.
(a) [early 17C–mid-19C] a nouveau riche, ostentatious person.
(b) [early 19C] fashion.
(c) [mid-19C+] ostentation, showiness, vulgarity.
(d) [1910s] (US Und.) a show-off, a braggart.
(e) [1920s–50s] (US Und.) a suit of clothes.
(f) [1920s+] (Aus.) one’s personal appearance.
2. [late 17C–18C] a periwig; thus rum flash n., a long, full, expensive wig; queer flash n., an old, raggedy wig [? its being worn by an ostentatious person, i.e. sense 1b above].
3. in the context of the criminal and/or sporting worlds.
(a) [mid-18C+] cant or criminal slang; also attrib.
(b) [19C] a generic term for the criminal underworld.
(c) [early 19C] sporting jargon.
4. with ref. to money or commodities (often counterfeit).
(a) [mid-19C+] (UK Und.) a large bundle of notes, esp. when used in a game of three-card monte to entice victims; thus make a flash v., to exhibit a large bundle of notes.
(b) [late 19C+] (UK Und.) imitation gold coins or banknotes; also attrib.
(c) [1920s+] (UK/US Und.) cheap but alluring items, e.g. cheap jewellery, used to lure players into carnival games, confidence tricks etc.
(d) (US) (genuine) jewels.
(e) [1960s] anything counterfeit.
(f) [1970s+] (US gay) cheap jewellery worn by homosexual males.
5. see flash of lightning under lightning n.
6. in senses of brevity .
(a) [late 19C–1950s] (orig. US) a quick look around.
(b) [20C+] (orig. US) a brief glimpse [initially a ref. to the conscious ‘flashing’ by striptease/burlesque artists].
(c) [1930s+] a brief glimpse when offered to a man by a woman inadvertently revealing her thighs, breasts or genitals; or vice versa, of a penis.
(d) [1980s] a sign of flirtatious behaviour.
7. in senses of suddenness.
(a) [late 19C–1970s] (US) a surprising piece of news or a rumour.
(b) [1920s+] (US) a burst of inspiration, a sudden idea.
(c) [1920s+] a flashback.
8. [1940s] a success.
9. in the context of drugs.
(a) [1940s+] the instantaneous effect that follows the injection of a narcotic or other drug; also in non-drug use.
(b) [1960s] a flashback to a previous psychotropic drug experience.
(c) [1960s+] the effect of LSD.
(d) [1970s+] LSD.
10. [1970s] a cigarette lighter.
11. [1970s] a general term of address.
[late 18C–mid-19C] to act in a vulgar manner, to show off.
[20C+] (Aus.) to show off, to be very well known or successful, to cut a ‘fine figure’.
[early 19C] in an attempt to show off; ‘a person who affects any particular habit, as swearing, dressing...taking snuff..., merely to be taken notice of, is said to do it “out of flash”’ (Vaux).
[19C] (UK Und.) to talk, usu. slang or underworld cant.
[1960s] (US Und.) to consume or otherwise use anything that is being displayed as a lure in a confidence trick.
[late 17C–mid-19C] (UK Und.) to talk in thieves’ cant.
SE in slang uses
see separate entries.
1. [late 19C] a gaudily dressed woman [‘upon the model of a rainbow’ (Ware)].
2. [1970s+] a sight [rhy. sl.].
see under lightning n.