Where does “ratfink” come from?

ratfink (English) comes from English rat, from Middle English raat, from Old English ræt, from Old English rætt, from Proto-Germanic rattaz, from Proto-Indo-European Hreh₃d- — to scrape.

ratfink (English): An informer or spy; a traitor; A dislikable or...

Definitions

  1. An informer or spy; a traitor; A dislikable or...

Ancestry of “ratfink”, step by step

ratfink traces back through two separate lines of ancestry.

via English rat

StepLanguageWordMeaning
1EnglishratA medium-sized rodent belonging to the genus...
2Middle EnglishraatAlternative form of ratte
3Old EnglishrætAlternative form of rætt
4Old Englishrættrat
5Proto-Germanicrattazrat
6Proto-Indo-EuropeanHreh₃d-to scrape

via English fink

StepLanguageWordMeaning
1EnglishfinkA contemptible person; An informer; A...
2AfrikaansvinkA finch
3DutchvinkA chaffinch; One of many other birds of the...
4Middle Dutchvinke—
5Proto-Germanicfinkizfinch
6Proto-Indo-European(s)pingoschaffinch
Every word from Proto-Indo-European Hreh₃d- →Every word from Proto-Germanic rattaz →Every word from Old English rætt →
ratfink — Etymology, Origin & Word History | Etymology Explorer