boorish charmer

While I cannot be 100% sure about it, it might be in reference to a sentence in Dryden, cited in the OED entry for boorish:
Quote:
1697 DRYDEN Virg. Ded., The Boorish Dialect of Theocritus has a secret Charm in it.
It (link) comes from Dryden's translation of Virgil's Eclogues, in the dedicatory preface. Theocritus was the inventor of bucolic poetry, of which the Eclogues are an example.

Ceci n'est pas un seing.