Green’s Dictionary of Slang

a miserable, gloomy person.

1836–7		Dickens Pickwick Papers (1999) 48: Rum fellow — does the heavy business — no actor — strange man — all sorts of miseries — dismal Jemmy, we call him on the circuit.
1880		Western Times 10 Mar. 2/4: Mr Johnson might have no great difficulty in defeating Mr Mills, one of them observing that ‘Dismal Jimmy’s’ time is nearly up.
1888		Yorks. Gaz. 26 May 10/5: One man [...] had won for himself the sobriquet of ‘Dismal Jimmy’.
1896		Notts. Guardian 23 May 4/3: Dr Cookson, the Vice-Chancellor irreverently known in those days as ‘Dismal Jimmy’.
1904		Manchester Courier 19 Mar. 19/6: It was stated that the deceased was nicknamed by his brother officers ‘Dismal Jimmy’.
1917		Aberdeen Jrnl 14 Dec. n.p.Optimism and pessimism were largely a matter of temperament. One man might be called ‘Cheerful Charley’ and another ‘Dismal Jimmy’: .
1927		Dundee Courier 19 Oct. 5/4: An incomprable dismal Jimmy who believes that [...] the country is going to the dogs.
1933		H.A. Vachell Vicar’s Walk in Partridge DSUE (1984) 314/2: A dog-in-the-manger, a spoil-sport, a wet blanket, a dismal jimmy.
1945		Dundee Courier 19 Oct. 2/4: [headline] [Sir Stafford] Cripps The Housewives’ Dismal Jimmy.
1954		Yorks. Eve. Post 10 Feb. 3/1: Mr Bridges, one-time mayor of Merthyr Tydful, denies being a dismal Jimmy.