Green’s Dictionary of Slang

1. (also fungus face) an unpleasant person.

1782		G. Parker Humorous Sketches 51: The subtile fungus told them all he knew.
1920		Ade Hand-made Fables 113: The local Fungi looked askance at the Cow-Puncher Hat.
1938		J.E. Hoover Persons in Hiding 123: Such persons as ambulance chasers, cappers for lawyers, bail bond fixers, and other forms of the fungus which feeds on the misfortunes of crime.
1957		Wash. Post 29 Sept. F1/1–2: ‘There’s fungus among us’ is taking the place of ‘creepy character’.
1961		Long Beach Press-Telegram 14 Dec. 8: A fungus among us means there’s a character in our midst.
1991		B. Quinn Smokey Hollow 149: The girl was unpopular – her nickname was Fungus Face.
2002		Guardian 17 July 1/1: Brett’s sister [...] shouted up to Mackenney’s relatives in the public gallery: ‘You slags, you fungus’.

2. a moustache; a beard; thus fungus-face n., an insult to a hirsuite male.

1909		P. Macgill ‘Down on the Dead End’ in Songs of the Dead End (1913) 130: His men and their fungous-white [sic] faces.
1918		R.H. Knyvett ‘Over There’ with the Australians 110: Few could shave, and you soon could not recognise the face of your best chum as it hid itself beneath a growth of some reddish fungus.
1929		Townsville Daily Bull. (Qld) 10 Aug. 16/2: The fungus on your face would nestle an adult flock of galahs.
1933		M. Marshall Tramp-Royal on the Toby 16: You can imagine what torture I underwent trying to shave off the stiff stubble of chin fungus.
1941		Aus. Women’s Wkly 26 July 22/2: A moustache is a ‘fungus’.
1951		D. Stivens Jimmy Brockett 118: How do you like me with the lip fungus?
1954		Wodehouse Jeeves and the Feudal Spirit 20: After the bad press the old fungus had been getting of late.
1959		I. & P. Opie Lore and Lang. of Schoolchildren (1977) 75: Someone with a beard has ‘Beardie!’ or ‘Fungus face!’ shouted after him.
1960		N. Hilliard Maori Girl 169: Have a nice night with old fungus-face.
1961		R.S. Close With Hooves of Brass 1124: ‘Well, Ziff - have you made up your mind about whipping that fungus off your face?’.
1963–74		B. Humphries Barry McKenzie [comic strip] in Complete Barry McKenzie (1988) 44: Cop this fungus face!
1971		F.J. Hardy Outcasts of Foolgarah (1975) 87: The fungus on the upper lip like a Hitler moustache.
2002		S. Maloney Something Fishy (2006) 119: On the lam, Syce had gone to ground, grown some fungus.
2007		S. Maloney Sucked In 203: Bishop stroked his fungus and gave it some thought.

3. an old man.

1915		M.G. Hayden ‘Terms Of Disparagement’ in DN IV:iii 203: fungus, an old man. ‘Pat, an Irish fungus, lives in that little shack.’.
2019		P. Baker Fabulosa 293/1: fungus an old man.
2023		R. Milward Man-Eating Typewriter 113: [T]heir teeniest, tightest trainees pairing off like a couple of ultra-domesticated funguses.