How can I condense these two sentences into one sentence?

Carl is using a defense mechanism known as displacement. Displacement is the transfer of an emotion from its original focus to another object, person, or situation.

I fixed your other sentences. Now it's your turn.

What do YOU THINK?

Carl is using a defense mechanism known as displacement, it is the transfer of an emotion from its original focus to another object, person, or situation.

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You have created a run-on.

Put a period after "displacement." Then decide how to make the words from "it is" onward into a complete sentence.

If I put a period after "displacement", wouldn't it be two sentences?

Could you take out some words?

Because you have two definitions of displacement, I would take out the first one. That is a really lengthy sentence.

As long as you make it clear what "it" is, it should be fine. What word/words could substitute for "it"?

But then you'll have two sentences. Isn't your assignment to combine them into one?

Yes, I need to combine them into one. I'm not sure what to replace "it" besides "displacement".

Be sure to read Lisa's suggestion above.

Carl is using displacement which is the transfer of an emotion from its original focus to another object, person, or situation.

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Carl is using displacement, a defense mechanism involving the transfer of an emotion from its original focus to another object, person, or situation.

You cannot leave out the words in bold above or you distort the original ideas.