Metaphorical use of “patricide”
In Swedish, the word for patricide (fadermord) is commonly used in a metaphorical sense for the act of the disciple, usually publicly, turning on their teacher or benefactor (which may be a person or an institution).
I have consulted several English dictionaries online, but none of them list an English equivalent of this metaphorical use of patricide, only the literal and judicial meaning of the word.
My question is therefore, if patricide is not generally used in this metaphorical sense in English, is there another word which conveys this specific nuance of treachery?
The Swedish usage usually implies a break with former convictions (passed down from one’s teacher or otherwise). It is not, therefore, a treachery for personal gain, but more often due to a change of convictions or beliefs.
In Swedish, it is also a fairly neutral term – fadermord in this sense is not morally despicable, though it may be tactless; it may even carry a note of enviable moral integrity.
Accepted answer: There are, of course, several ways in which this expression can be rendered in English. Among the answers below, "renegade" or "apostate" seem to be the closest single words, with "judas" a close third. By using an idiom, "the worm has turned to bite the hand that feeds it," though a bit quirky, can come quite close.
Since the word in Swedish has context dependent moral implications, which is not the case for the closest English equivalents, the appropriate word will have to be decided by the context.
Solution 1:
While apostate specifically means “a person who has renounced a religion or faith”, it often is used figuratively to mean a person who has renounced any particular belief or policy.
Apostate may have more negative connotations than desired. Note the negative slants in several senses (as noun and adjective) given under the heading Apostate in OED1 (1888):
A. sb. 1. One who abjures or forsakes his religious faith, or abandons his moral allegiance ; a pervert.
2. One who deserts his party, or forsakes his allegiance or troth ; a turncoat, a renegade.
B. adj. 1. Unfaithful to religious principles or creed, or to moral allegiance ; renegade, infidel ; rebellious.
Also consider turncoat (“A traitor; one who turns against a previous affiliation or allegiance”), with synonyms that include apostate, defector, renegade (“A disloyal person who betrays or deserts his cause, religion, political party, friend, etc”), and traitor, besides related terms like recreant, rebel, and aforementioned judas.
The comparison of several of these terms given in Merriam-Webster's Dictionary of Synonyms may be helpful. A brief quote from that link: “Apostate therefore usually connotes surrender, but it need not, as renegade often does, imply treachery or hostility to what is forsaken...”
Solution 2:
I think the particular type of betrayal would be understood if you called that person a Judas.
Solution 3:
The great news is that patricide is indeed not as often used in this way in English. Since the metaphor is still understandable, this means you would have writing that is fresh and interesting, rather than clichéd and derivative.
Solution 4:
I'm not sure that there is a single word, but the expressions
Bite the hand that feeds
The worm has turned
may both suffice. The first has exactly the connotation you ask about; the second is more to do with confidence and rebellion against being downtrodden.