E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Shilling.
Said to be derived from St. Kilian, whose image was stamped on the shillings of Würzburg. Of course this etymology is of no value. (Anglo-Saxon, scylling or scilling, a shilling.)
1
According to Skeat, from the verb scylan (to divide). The coin was originally made with a deeply-indented cross, and could easily be divided into halves or quarters.