Q: Does "air" have the same meaning in the following two sentences?

The flock of birds took to the air.

Open a window and let in some air.

A: the same meaning

Q: Does "plagiarism" have the same meaning in the following two sentences?

Even if it's not illegal, plagiarism is usually frowned upon.

Copy from one, it's plagiarism. Copy from two, it's research.

A: the same meaning

Q: Does "crunch" have the same meaning in the following two sentences?

A financial crunch.

An end-of-the year crunch.

A:
the same meaning