Green’s Dictionary of Slang

rustic, boorish.

1599		Jonson Every Man Out of his Humour characters: Sordido, a wretched hobnailed chuff.
1628		J. Earle Micro-Cosmographie F5: A Plaine Country Fellow [...] Hee [...] has some thrifty Hobnaile Prouerbs to clout his discourse.
1657		J. Poole English Parnassus 158: Plough-man. v. Clown. Rustick, sordid, [...] clownish, sturdie, rude, sweating, sallow, hide-bound, hobnail'd.
1666		London undone n.p.: But that those Hobnail'd Clowns should be so chubbish, / Whom though we knew much baser then our rubbish: / Those pilfering Country-Coridons.