The group carries two histories. In Greek outside the Bible it means placating a person; in the Septuagint it renders the Hebrew kipper, whose objects are sins, persons and holy places rather than God. C. H. Dodd argued from the second, Leon Morris from the presence of wrath in the argument of Romans, and neither case has displaced the other. English versions have chosen differently in each generation, and the choice usually follows the doctrine already held.
What would resolve this A lexical study covering the whole hilask- group across the Septuagint, the Jewish Greek literature outside it and the papyri, treating the New Testament occurrences last rather than first. The question is whether the Septuagint usage displaced the ordinary Greek sense for these writers or merely sat beside it.
OpenSeptuagint studies; New Testament lexicography; Hellenistic Greek philologyF. L. Cross and E. A. Livingstone (eds.), The Oxford Dictionary of the Christian Church, 3rd revised edition