slang. [According to Slang Dict., from Danubian-Gipsy cuta gold coin.] A sovereign.

1

1846.  R. L. Snowden, Magistr. Assist., 346. I … got six Finnips and a Cooter for the Yacks.

2

1851.  Mayhew, Lond. Labour, I. 312/1. Upon which the ‘swells’ … ‘come down with a couter’ (sovereign).

3

1880.  J. Payn, Confid. Agent, I. 207 (Farmer). Well, he gave us half a couter at all events.

4