Green’s Dictionary of Slang

1. a large white wig ‘such as is commonly worn by the dignified clergy, and was formerly by physicians’ (Grose, 1785); also attrib.

1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1794		Sporting Mag. Mar. III 327/2: An elderly person [...] in a cauliflower wig, cocked hat, black breeches and boots.
1811		Lex. Balatronicum.
1825		‘Bubble & Squeak & Pettitoes’ in Universal Songster I 7/1: There was one Mr Grig / Wore a cauliflower wig.
1852		Fife Herald 19 Aug. 1/7: An impossible shepherd, in blue satin trunks, [and] a cauliflower wig.
1859		Cheshire Obs. 16 July 8/1: My father wears a cauliflower wig.
1863		(ref. to late 18C) Middx Chron. 16 July 5/5: In revolutionary days [...] the three learned professions, the Church, Law and Phtysic, adhered to the cauliflower wig.
1875		Reynolds’s Newspaper 7 Nov. 3/1: The mouldy, wandering old judge in his cauliflower wig.
1881		(ref. to 18C) Aberdeen jrnl 3 Dec. 1/6: The precentor, who was a little old man, with a cauliflower, full-bottomed wig, such as was worn by old men in those days.

2. one who wears powder in their hair.

1823		‘Jon Bee’ Dict. of the Turf, the Ring, the Chase, etc. 22: Cauliflower — any one who wears powder on his head.
1845		J. Lindridge Sixteen-String Jack 117: It would be the worse for all of us if we had our deserts, old cauliflower.

3. the foaming top of a newly poured glass of beer.

1933		‘William Juniper’ True Drunkard’s Delight.
1937–84		Partridge DSUE (1984) 192/2: from ca. 1870.

4. a ‘cauliflower ear’, the sign of a boxer whose ears have taken too many punches to retain their original shape [abbr. SE].

[1900		Bulletin (Sydney) 9 June 24/3: Talking of that peculiar development known to the cognoscenti as the ‘cauliflower-ear,’ and brought about by frequent bashes in the shape of swings (right and left) on the aural organ, writer mentioned that it was strange that the big black escaped unscathed in this way].
1905		Omaha Dly Bee (NE) 11 June 33/4: My left ear is of the variety known as cauliflower because of having been struck by a prizefighter.
1915		Cheffield Indep. 26 Jan. 8/4: After the fifteenth round [...] his left ear had [...] assumed the ‘caulilower’ proportion.
1920		N.Y. Tribune 27 Oct. 13/4: They call it Cauliflower Alley. It is the room where the pork-and-beaners and their managers gather [...] It is written of pork-and-beaners, ‘By their ears you shall know them’.
1934		Dan Burley Plaindealer (Kansas City) 2 Nov. 6/1: The boys who seek honors among the cauliflowers [...] have the misfortune to get in the same ring with the demonic slugger from the Motor City.
1969		‘Iceberg Slim’ Mama Black Widow 179: I saw a pulpy growth behind an ear — a prize fighter’s cauliflower!

5. in ext. use of sense 3, the head.

1915

S. Ford Torchy, Private Sec. 27: It must have been sort of hopeless at the start, inoculatin’ a cauliflower like mine with higher chemistry.

6. by metonymy, based on sense 4, a boxer.

1946

C.S. Montanye ‘Don’t Meddle with Murder’ in Thrilling Detective May 🌐 The two cauliflowers were going at it tongs and hammer.

7. attrib. use of sense 6, pertaining to prizefighting.

1927		H.E. Rockwell ‘Color Stuff’ in AS III:1 29: He terms his own jargon the ‘cauliflower vernacular’.
1938		A.J. Liebling Back Where I Came From (1990) 109: In the lush days of the cauliflower boom, the game was invaded by cloak-and-suiters [...] seeking to invest their surplus profits in prizefighters.
1947		Sun. Times (Perth) 18 May 11s/1: I’ve been turning back the pages of my old sporting scrap-book — looking down Cauliflower Row. Fistic phizzogs that have thrilled the fans.