counterpleaded

For because they did not write down, therefore, as the sole mode of providing for accurate remembrance, they were obliged to compose in a very elaborate metre; in which the mere _pattern_ as it were of the verse, so intricate and so closely interlocked, always performed thus two services: first, it assisted the memory in mastering the tenor; but, secondly, it checked and counterpleaded to the lapses of memory or to the artifices of fraud.

The Posthumous Works of Thomas De Quincey, Vol. 2 Thomas De Quincey 1822