What is Melius Inquirendum Vel Inquirendo?

Legal Definition
English practice. A writ which in certain cases issues after an imperfect inquisition returned on a capias utlugatum in outlawry. This melius inquirendum commands the sheriff to summon another inquest in order that the value, &c., of lands, &c., may be better or more cor- rectly ascertained. Its use is rare.
-- Bouviers Law Dictionary