+2 for Knukkle!
I would take that or exponentiation because every element of the analogy is a common noun.
Level 4:
A compound word is a word that consists of two separate words which put together produce the compound word. Examples are paper/clip and lady/bug. What compound word means exactly the same as each of the words that make it up?
[Hint: 4 letters, then 3 letters]
________ __________
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