Green’s Dictionary of Slang

countrified, gullible.

1666		epigraph to Marvell ‘The Second Advice to a Painter’ in Lord Poems on Affairs of State (1963) I 35: The high-sho’d plowman, should he quit the land, / To take the pilot’s rudder in his hand.
1688		T. Shadwell Squire of Alsatia I i: The Conversation of unthinking Hunting, Hawking Block-heads, or High-shoo’d Peasants.