UNFATHOMABLE – Encyclopedic Dictionary of Bible and Theology

anexeraunetos or anexereunetos (ajnexerauvnhto”, 419), (a, privative; n, euphonic; ex or ek, outside; eraunao, search, examine), is used in Rom 11:33, of the judgments of God: “unfathomable” ( RVR, RVR77; RV: “incomprehensible”; VM,: “uninvestigatable”).¶

Source: Vine New Testament Dictionary