A. caste → Portuguese (III)
Caste entered English via Portuguese casta, meaning “breed, lineage, race.”
Portuguese traders and missionaries used the word while describing the Indian social system.
Later, it was absorbed into English with its present sociological meaning.
B. beef → French (IV)
Beef comes from Old French boef / buef, ultimately from Latin bovem (ox).
After the Norman Conquest (1066), many food terms in English came from French, while animal names often remained Germanic:
cow (Old English) → beef (French)
sheep → mutton
pig → pork
C. blunder → Norse (I)
Blunder derives from Old Norse blundra, meaning “to shut one’s eyes” or “to stumble blindly.”
The semantic shift:
“to act blindly” → “to make a foolish mistake”
This reflects strong Scandinavian influence on English during the Viking settlements.
D. flak → German (II)
Flak is a 20th-century borrowing from German Flugabwehrkanone
(literally: “aircraft-defence gun”).
It entered English during World War II, initially as a military term and later metaphorically (“to receive flak”).