Charles Cullen posed a peculiar puzzle in "Linear Algebra and Differential Equations": Why is an eigenvalue like liverwurst? Like pearls before swine or caviary to the general, this query was little appreciated by the would-be engineers struggling to fulfill their mathematics requirement, and they would have hardly have been enlightened by the answer in the back of the book: Beide Woerter sind halb Englisch, halb Deutsch.
I have the impression that I got the impression from Professor Cullen that he thought this pair of words were unique in this respect. I can't recall now whether he ever said so, but I let myself think so for some years... although now I realize that with a little thought, it's possible to come up with a few more such examples.
And so our little "Liverwurst List":