a. With become. to become good for: (Scottish) to take responsibility for another's performance of an undertaking; to stand surety. Now rare.Sc. National Dict. records this sense as still in use in 1955.
ΚΠ
1645 S. RutherfordTryal & Triumph of Faith vii. 49 He is become good to the Father for us.
1828 D. M. MoirLife Mansie Wauch xviii. 265 I tell't Maister Wiggie,..that I could almost become guid for your being mair wary of your conduct for the future time to come.