Green’s Dictionary of Slang

1. a beard.

1916		J. Lait ‘One Touch of Art’ in Beef, Iron and Wine (1917) 212: That was the sure-fire combination—the actor and the whiskers—ham and spinach.
1921		N. Putnam West Broadway 134: One was a fat man with a round baby face, and the other a little bird with spinach, French style.
1933		Ersine Und. and Prison Sl.
1944		J. Archibald ‘Defective Bureau’ in Popular Detective 🌐 He changed his name, grew spinach, and treated crooks who got nicked by bullets.
1960, 1975		Wentworth & Flexner DAS 509/1: Since c.1900.

2. a moustache.

1917		R. Lardner ‘Three Kings and a Pair’ in Gullible’s Travels 59: I looked at the pitchers o’ the different actors, hung up on the posts to advertise some kind o’ hair tonic [...] I suppose most o’ them meant Goatee or Spinach or Brush or Hedge or Thicket or somethin’.
1922		M.E. Smith Adventures of a Boomer Op. 63: My friend with the spinach, got out, got down, and got under.
1929		W. Winchell On Broadway 1 Oct. [synd. col.] His att[orney]’d made Peacox shave his lip spinach.
1949		Monteleone Criminal Sl. (rev. edn) 220: spinach Whiskers.

3. pubic hair.

1927–41

in G. Legman Limerick (1953) 35: There was a young fellow of Greenwich / Whose balls were all covered with spinach.

4. money; dollar bills [like the vegetable, it is green].

1907		Sun (NY) 18 Oct. 11/1: He sees the educated spinach swinging his way at the tracks.
1927		D. Hammett ‘The Big Knockover’ Story Omnibus (1966) 299: What, no spinach? [...] Nobody gave you anything to give to me?
1938		D. Burley N.Y. Amsterdam News 19 Feb. 17: You’re allright if your spinach supply holds out.
1950		T. Thursday ‘Hart Failure’ in All Sports Aug. 🌐 I am a sappo for not risking a bob or two, as I can use some extra spinach.
1989		(con. 1960) P. Theroux My Secret Hist. (1990) 174: That’s not spinach. That’s cash.
2000		(con. 1940s–60s) Décharné Straight from the Fridge Dad.