I find it rather hard to look up the word "blameshift" in a dictionary. It appears in some dictionaries, but not many. The one dictionary I have found it in is Wiktionary. But I was unable to find this word, hyphenated or un-hyphenated, in Merriam Webster's online dictionary, or Collins' online dictionary.
Wiktionary gives the following definition:
(biblical) To blame another for one's own wrong-doing. Blameshifting can be caused by pointing the finger at another when trying to save one's skin.
I find it very interesting that they consider this word to be biblical. Does it appear in any English translations of the Bible? But more importantly, could anyone explain the etymology of the word "blameshift"? How long has this word been around? I know that the word "blame" ultimately comes from Ancient Greek (βλασφημέω) but I would be interested to know how exactly the compound word, "blameshift", came about.
I woud like to caution you, by the way, not to write off the etymology as that of two separate words: "blame" and "shift". The above questions that I ask are far more specific. I am interested in when and where these words came together, to form a compound. I am interested to know why many dictionaries do not list this compound word. I am interested in why Wiktionary thinks it is biblical. You can probably tell by now that my questions go beyond the etymology of its parts: I am interested in the etymology of the whole.