E. Cobham Brewer 1810–1897. Dictionary of Phrase and Fable. 1898.
Exter.
That’s Exter, as the old woman said when she saw Kerton. This is a Devonshire saying, meaning, I thought my work was done, but I find much still remains before it is completed. “Exter” is the popular pronunciation of Exeter, and “Kerton” is Credition. The tradition is that the woman in question was going for the first time to Exeter, and seeing the grand old church of Kerton (Crediton), supposed it to be Exeter Cathedral. “That’s Exter,” she said, “and my journey is over;” but alas! she had still eight miles to walk before she reached her destination.
