(A). The framing erected between piers to hold up the stones of an arch during the making thereof.
“Certain crude beliefs may be needful in the infancy of a nation, but when the arch is made, when the intelligence is fully developed, the cinter is thrown down and truth stands unsupported.” —E. D. Fawcett.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894