a. Obs. rare–1. [f. L. effrēn-us unbridled (f. ex out + frēn-um bridle) + -ABLE.] Incapable of restraint, violently rebellious.

1

1621.  Bolton, Stat. Irel., 313 (an. 11 Eliz.). The saide traytor having by this effrenable meanes growen to great power.

2