Generate a topic word for the given sentence. A topic word is usually the name of a person, place, animal, concept or object the sentence is focusing on.

Q: meaning is a term in linguistics and philosophy.

A: meaning
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Q: the first and only written biography of doug henning, "spellbound: the wonder-filled life of doug henning" was published in 2009 (john harrison, boxoffice books, new york.)

A: doug henning
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Q: if two numbers have the same order of magnitude, they are about the same size.

A:
order of magnitude
****