I happened in one day to come across the words “susurrus” and “susurrate” in two different books (Marilynne Robinson’s Gilead and Tom McCarthy’s C). Finding the coincidence delightful, I went home and told my wife about the new word(s) I had learned.
“Ahh, sussurate,” she whispered. It took me a while to realise that my wife, the non-native English speaker, knew a word I had just learned. Silly me, forgetting that all these wonderfully obscure Latinate words in English are basic vocabulary in Spanish.