Green’s Dictionary of Slang

a public house game played with a button or coin.

1830		Morn. Advertiser 18 Jan. 3/5: Baker gave evidence [...] He had never seen the game before. Mr. Laing.— What did they call it? Baker.— ‘Quod him,’ your Worship. I learned that they called it ‘Coddam, or Coddum, or Quod him’.
1864, 1867, 1870		Hotten Sl. Dict. 105: coddam, a low public-house game, much affected by medical students and cabmen, three to each side.
1870		London & Provincial Entr’acte 1 Oct. 6/2: Bruise me if we don’t go and have it out at ‘coddem’.
1885		Good Words Aug. 530: Some prefer coddam, and risk their pint of beer on the discovery of the coin [F&H].
1890		Pall Mall Gazette 1 Mar. 5, col. 2: The boys were playing a game called coddom, a guessing game [F&H].
1910		(ref. to 1890s) Meek & Wells George Meek, Bath Chair-Man 78: Here, during the winter, we spent many lively evenings, playing cribbage [...] ‘tippet,’ a variation of the game of ‘cod ’em’.