Webster's Revised Unabridged Dictionary · 1913

Eyre

Eyre (âr) , noun

[Old French erre journey, march, way, from Latin iter, itineris, a going, way, from the root of ire to go. Compare Errant, Itinerant, Issue.]

(O. Eng. Law) A journey in circuit of certain judges called justices in eyre (or in itinere).

They were itinerant judges, who rode the circuit, holding courts in the different counties.